Wifi slows down when Bluetooth headset is connected in Ubuntu 20.04

My wifi works perfectly until I connect my system to a Bluetooth headset. After connecting to the Bluetooth headset my wifi slows down a lot. I tried solution from this and this questions but nothing worked.

The output of lspci -knn | grep Net -A2

02:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter [10ec:b723]
    DeviceName: Sanji2 
    Subsystem: Hewlett-Packard Company RTL8723BE PCIe Wireless Network Adapter [103c:81c1]
    Kernel driver in use: rtl8723be
    Kernel modules: rtl8723be

thanks in advance :)

Edit 1

Output of sudo iwlist freq

lo        no frequency information.

enp1s0    no frequency information.

wlo1      13 channels in total; available frequencies :
          Channel 01 : 2.412 GHz
          Channel 02 : 2.417 GHz
          Channel 03 : 2.422 GHz
          Channel 04 : 2.427 GHz
          Channel 05 : 2.432 GHz
          Channel 06 : 2.437 GHz
          Channel 07 : 2.442 GHz
          Channel 08 : 2.447 GHz
          Channel 09 : 2.452 GHz
          Channel 10 : 2.457 GHz
          Channel 11 : 2.462 GHz
          Channel 12 : 2.467 GHz
          Channel 13 : 2.472 GHz
          Current Frequency:2.447 GHz (Channel 8)

Edit 2

ant_sel=1 doesn't gives any noticeable change

ant_sel=2 results in 'no network found` (Ubuntu unable to find any wifi network)

parag@Notebook:~$ cat /etc/modprobe.d/rtl8723be.conf 
options rtl8723be ant_sel=2 swlps=0
parag@Notebook:~$ iwlist scan | egrep -i 'ssid|level'
lo        Interface doesn't support scanning.

enp1s0    Interface doesn't support scanning.

also Output of modeinfo rtl8723be

filename:       /lib/modules/5.11.0-25-generic/kernel/drivers/net/wireless/realtek/rtlwifi/rtl8723be/rtl8723be.ko
firmware:       rtlwifi/rtl8723befw_36.bin
firmware:       rtlwifi/rtl8723befw.bin
description:    Realtek 8723BE 802.11n PCI wireless
license:        GPL
author:         Realtek WlanFAE <[email protected]>
author:         PageHe  <[email protected]>
srcversion:     17AE822AE3E2EAA1A500831
alias:          pci:v000010ECd0000B723sv*sd*bc*sc*i*
depends:        rtlwifi,rtl8723-common,rtl_pci,btcoexist,mac80211
retpoline:      Y
intree:         Y
name:           rtl8723be
vermagic:       5.11.0-25-generic SMP mod_unload modversions 
sig_id:         PKCS#7
signer:         Build time autogenerated kernel key
sig_key:        0D:27:87:4B:73:30:80:92:F7:26:14:3F:FE:83:1E:48:91:08:F2:86
sig_hashalgo:   sha512
signature:      43:63:EC:A3:6A:63:26:D9:16:9F:D5:8C:B0:B9:D5:24:FF:D7:FD:39:
        89:57:BA:4A:F1:87:DD:8A:90:6F:8B:C7:78:77:59:E5:E4:6C:93:B8:
        42:94:86:8A:4F:62:AA:29:DA:C8:AC:6D:D5:19:15:36:24:7D:2A:E7:
        7D:C7:70:2E:69:35:28:17:42:A0:68:05:20:FB:64:1C:75:5D:CA:B7:
        A2:51:81:00:08:93:54:2A:7B:3B:1A:3F:33:0D:E9:B9:5C:E2:30:15:
        E2:59:C5:96:BE:B0:CE:5F:72:8E:63:B4:4E:10:62:F8:7E:A1:27:9C:
        AA:7C:47:E0:5C:59:E7:68:E9:B4:5F:2B:3D:83:59:0B:E9:AD:61:48:
        21:F9:60:CC:BC:BA:3F:4E:25:7F:72:DA:87:07:96:F6:F5:EF:E7:4E:
        67:7E:77:67:74:11:1C:7D:A7:E2:54:7E:45:BE:D9:21:AF:AE:E1:BA:
        68:DB:0A:1E:2A:33:35:B5:8C:E4:ED:F4:3A:98:08:80:E3:BB:19:C6:
        B6:CC:57:1F:1B:BC:6F:DA:A0:F3:87:48:E3:F4:F6:0B:1B:06:4F:A9:
        C9:F3:5F:40:A4:D2:BF:BF:19:C5:ED:0F:6E:25:2A:41:93:CC:E8:D9:
        F1:6F:3E:AD:EB:80:3C:F9:53:E4:91:12:3D:EE:6C:70:B6:DB:73:8A:
        01:D8:84:56:D9:CE:28:D1:8D:55:07:EF:D5:CB:71:23:3F:63:21:07:
        BB:F9:FF:DC:DD:24:85:B5:DA:0A:60:A9:D1:49:ED:52:97:72:CB:87:
        96:7F:FD:85:EA:35:55:E9:AD:D6:3E:D2:43:23:C2:11:26:7B:57:C9:
        71:24:32:35:FE:5D:80:56:CD:4C:EC:1A:54:65:64:78:0D:88:32:08:
        2C:97:0B:D6:2C:36:20:F6:66:C2:FC:AB:55:E6:DB:82:52:ED:00:70:
        E3:28:B9:5C:BE:A1:88:8A:3A:F4:C9:E5:6E:A6:4A:2D:DB:7B:5F:49:
        86:C6:4C:4E:9C:62:BD:23:60:23:8C:46:54:B2:CA:79:63:2A:82:B1:
        46:4B:97:CC:3B:64:57:BD:70:AD:CE:3F:DC:42:D2:B1:C0:13:BB:4C:
        72:A4:0F:9A:C3:0B:84:01:E8:B9:53:0C:80:DB:8E:E2:46:12:B1:B1:
        73:35:F9:94:3A:FD:7F:1A:22:91:B8:1F:BA:DA:87:97:9A:CF:D5:A9:
        08:B7:62:B6:6E:28:64:84:50:C2:D2:7B:B7:BB:98:12:62:26:CC:FB:
        A3:FE:8D:F7:4F:AD:C3:C6:EF:62:DC:A6:02:8C:5D:1F:26:E7:30:D0:
        30:4E:A2:04:3C:EE:9A:9D:A5:C1:24:A1
parm:           swenc:Set to 1 for software crypto (default 0)
 (bool)
parm:           ips:Set to 0 to not use link power save (default 1)
 (bool)
parm:           swlps:Set to 1 to use SW control power save (default 0)
 (bool)
parm:           fwlps:Set to 1 to use FW control power save (default 1)
 (bool)
parm:           msi:Set to 1 to use MSI interrupts mode (default 0)
 (bool)
parm:           aspm:Set to 1 to enable ASPM (default 1)
 (int)
parm:           debug_level:Set debug level (0-5) (default 0) (int)
parm:           debug_mask:Set debug mask (default 0) (ullong)
parm:           disable_watchdog:Set to 1 to disable the watchdog (default 0)
 (bool)
parm:           ant_sel:Set to 1 or 2 to force antenna number (default 0)
 (int)

Edit 3

1. Output of commands

parag@Notebook:~$ uname -a
Linux Notebook 5.11.0-25-generic #27~20.04.1-Ubuntu SMP Tue Jul 13 17:41:23 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

parag@Notebook:~$ sudo lshw -class network
  *-network                 
       description: Ethernet interface
       product: RTL810xE PCI Express Fast Ethernet controller
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:01:00.0
       logical name: enp1s0
       version: 07
       serial: 30:e1:71:73:d8:3f
       capacity: 100Mbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=5.11.0-25-generic firmware=rtl8106e-1_0.0.1 06/29/12 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:16 ioport:4000(size=256) memory:b1200000-b1200fff memory:b1000000-b1003fff
  *-network
       description: Wireless interface
       product: RTL8723BE PCIe Wireless Network Adapter
       vendor: Realtek Semiconductor Co., Ltd.
       physical id: 0
       bus info: pci@0000:02:00.0
       logical name: wlo1
       version: 00
       serial: 58:00:e3:88:1f:93
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=rtl8723be driverversion=5.11.0-25-generic firmware=N/A ip=192.168.1.11 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       resources: irq:17 ioport:3000(size=256) memory:b1100000-b1103fff

parag@Notebook:~$ ls -al /etc/pm/config.d/
ls: cannot access '/etc/pm/config.d/': No such file or directory

parag@Notebook:~$ ls -al /etc/modprobe.d/
total 60
drwxr-xr-x   2 root root  4096 Aug 13 13:24 .
drwxr-xr-x 137 root root 12288 Aug 12 15:51 ..
-rw-r--r--   1 root root  2507 Jul 31  2015 alsa-base.conf
-rw-r--r--   1 root root   154 Feb 16  2020 amd64-microcode-blacklist.conf
-rw-r--r--   1 root root   325 Mar 12  2020 blacklist-ath_pci.conf
-rw-r--r--   1 root root  1518 Mar 12  2020 blacklist.conf
-rw-r--r--   1 root root   210 Mar 12  2020 blacklist-firewire.conf
-rw-r--r--   1 root root   677 Mar 12  2020 blacklist-framebuffer.conf
-rw-r--r--   1 root root   156 Jul 31  2015 blacklist-modem.conf
lrwxrwxrwx   1 root root    41 Jul 17 22:15 blacklist-oss.conf -> /lib/linux-sound-base/noOSS.modprobe.conf
-rw-r--r--   1 root root   583 Mar 12  2020 blacklist-rare-network.conf
-rw-r--r--   1 root root   154 Nov 12  2020 intel-microcode-blacklist.conf
-rw-r--r--   1 root root   347 Mar 12  2020 iwlwifi.conf
-rw-r--r--   1 root root    28 Aug 14 08:18 rtl8723be.conf

parag@Notebook:~$ sudo lsmod | grep rtl8723be
rtl8723be              98304  0
btcoexist             155648  1 rtl8723be
rtl8723_common         24576  1 rtl8723be
rtl_pci                28672  1 rtl8723be
rtlwifi                94208  4 rtl_pci,rtl8723be,btcoexist,rtl8723_common
mac80211             1024000  3 rtl_pci,rtl8723be,rtlwifi

parag@Notebook:~$ sudo iwconfig
lo        no wireless extensions.

enp1s0    no wireless extensions.

wlo1      IEEE 802.11  ESSID:"FTTH-5731"  
          Mode:Managed  Frequency:2.452 GHz  Access Point: 00:6D:61:D8:57:31   
          Bit Rate=72.2 Mb/s   Tx-Power=20 dBm   
          Retry short limit:7   RTS thr=2347 B   Fragment thr:off
          Encryption key:off
          Power Management:on
          Link Quality=54/70  Signal level=-56 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:857   Missed beacon:0

parag@Notebook:~$ inxi -Fxz
System:    Kernel: 5.11.0-25-generic x86_64 bits: 64 compiler: N/A Desktop: Gnome 3.36.9 
           Distro: Ubuntu 20.04.2 LTS (Focal Fossa) 
Machine:   Type: Laptop System: HP product: HP Notebook v: Type1ProductConfigId serial: <filter> 
           Mobo: HP model: 81EB v: 61.38 serial: <filter> UEFI: Insyde v: F.21 date: 10/27/2016 
Battery:   ID-1: BAT1 charge: 28.6 Wh condition: 32.6/32.1 Wh (101%) model: Hewlett-Packard PABAS0241231 status: Discharging 
CPU:       Topology: Dual Core model: Intel Core i3-6006U bits: 64 type: MT MCP arch: Skylake rev: 3 L2 cache: 3072 KiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 15999 
           Speed: 1800 MHz min/max: 400/2000 MHz Core speeds (MHz): 1: 1803 2: 1926 3: 1802 4: 1816 
Graphics:  Device-1: Intel Skylake GT2 [HD Graphics 520] vendor: Hewlett-Packard driver: i915 v: kernel bus ID: 00:02.0 
           Display: x11 server: X.Org 1.20.11 driver: i915 resolution: 1366x768~60Hz 
           OpenGL: renderer: Mesa Intel HD Graphics 520 (SKL GT2) v: 4.6 Mesa 21.0.3 direct render: Yes 
Audio:     Device-1: Intel Sunrise Point-LP HD Audio vendor: Hewlett-Packard driver: snd_hda_intel v: kernel bus ID: 00:1f.3 
           Sound Server: ALSA v: k5.11.0-25-generic 
Network:   Device-1: Realtek RTL810xE PCI Express Fast Ethernet vendor: Hewlett-Packard driver: r8169 v: kernel port: 4000 
           bus ID: 01:00.0 
           IF: enp1s0 state: down mac: <filter> 
           Device-2: Realtek RTL8723BE PCIe Wireless Network Adapter vendor: Hewlett-Packard driver: rtl8723be v: kernel 
           port: 3000 bus ID: 02:00.0 
           IF: wlo1 state: up mac: <filter> 
Drives:    Local Storage: total: 931.51 GiB used: 26.69 GiB (2.9%) 
           ID-1: /dev/sda vendor: Western Digital model: WD10JPVX-60JC3T0 size: 931.51 GiB temp: 37 C 
Partition: ID-1: / size: 48.97 GiB used: 26.66 GiB (54.4%) fs: ext4 dev: /dev/sda7 
Sensors:   System Temperatures: cpu: 45.5 C mobo: 29.8 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 295 Uptime: 29m Memory: 7.67 GiB used: 3.59 GiB (46.8%) Init: systemd runlevel: 5 Compilers: gcc: N/A 
           Shell: bash v: 5.0.17 inxi: 3.0.38 

2. Brand/Model of computer : HP 15-ay542tu
3. Stay's like this

Also

1. setting swlps=0

parag@Notebook:~$ sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be swlps=0 fwlps=0"
options rtl8723be swlps=0 fwlps=0
parag@Notebook:~$ cat /etc/modprobe.d/rtl8723be.conf
options rtl8723be swlps=0 fwlps=0
parag@Notebook:~$ iwlist scan | egrep -i 'ssid|quality'
lo        Interface doesn't support scanning.

enp1s0    Interface doesn't support scanning.

                    Quality=58/70  Signal level=-52 dBm  
                    ESSID:"FTTH-5731"

Outputs

Internet Speed difference (average of 3 readings from fast.com)

12.3Mbps (without bluetooth headset)
1.8Mbps (with buletooth headset)

parag@Notebook:~$ cat /etc/modprobe.d/rtl8723be.conf
options rtl8723be swlps=0 fwlps=0
parag@Notebook:~$ grep [[:alnum:]] /sys/module/rtl8723be/parameters/*
/sys/module/rtl8723be/parameters/ant_sel:0
/sys/module/rtl8723be/parameters/aspm:1
/sys/module/rtl8723be/parameters/debug_level:0
/sys/module/rtl8723be/parameters/debug_mask:0
/sys/module/rtl8723be/parameters/disable_watchdog:N
/sys/module/rtl8723be/parameters/fwlps:N
/sys/module/rtl8723be/parameters/ips:Y
/sys/module/rtl8723be/parameters/msi:N
/sys/module/rtl8723be/parameters/swenc:N
/sys/module/rtl8723be/parameters/swlps:N
parag@Notebook:~$ iwlist scan | egrep -i 'ssid|quality'
lo        Interface doesn't support scanning.

enp1s0    Interface doesn't support scanning.

                    Quality=60/70  Signal level=-50 dBm  
                    ESSID:"FTTH-5731"

2. ant_sel=1

parag@Notebook:~$ sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=1"
options rtl8723be ant_sel=1
parag@Notebook:~$ cat /etc/modprobe.d/rtl8723be.conf
options rtl8723be ant_sel=1
parag@Notebook:~$ iwlist scan | egrep -i 'ssid|quality'
lo        Interface doesn't support scanning.

enp1s0    Interface doesn't support scanning.

                    Quality=62/70  Signal level=-48 dBm  
                    ESSID:"FTTH-5731"

Outputs

speed: no major difference

parag@Notebook:~$ cat /etc/modprobe.d/rtl8723be.conf
options rtl8723be ant_sel=1
parag@Notebook:~$ grep [[:alnum:]] /sys/module/rtl8723be/parameters/*
/sys/module/rtl8723be/parameters/ant_sel:1
/sys/module/rtl8723be/parameters/aspm:1
/sys/module/rtl8723be/parameters/debug_level:0
/sys/module/rtl8723be/parameters/debug_mask:0
/sys/module/rtl8723be/parameters/disable_watchdog:N
/sys/module/rtl8723be/parameters/fwlps:Y
/sys/module/rtl8723be/parameters/ips:Y
/sys/module/rtl8723be/parameters/msi:N
/sys/module/rtl8723be/parameters/swenc:N
/sys/module/rtl8723be/parameters/swlps:N
parag@Notebook:~$ iwlist scan | egrep -i 'ssid|quality'
lo        Interface doesn't support scanning.

enp1s0    Interface doesn't support scanning.

                    Quality=64/70  Signal level=-46 dBm  
                    ESSID:"FTTH-5731"

3. ant_sel=2

parag@Notebook:~$ sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=2"
options rtl8723be ant_sel=2
parag@Notebook:~$ cat /etc/modprobe.d/rtl8723be.conf
options rtl8723be ant_sel=2
parag@Notebook:~$ iwlist scan | egrep -i 'ssid|quality'
lo        Interface doesn't support scanning.

enp1s0    Interface doesn't support scanning.

                    Quality=64/70  Signal level=-46 dBm  
                    ESSID:"FTTH-5731"

Outputs:

No wifi network was found in setting -> wifi

parag@Notebook:~$ cat /etc/modprobe.d/rtl8723be.conf
options rtl8723be ant_sel=2
parag@Notebook:~$ grep [[:alnum:]] /sys/module/rtl8723be/parameters/*
/sys/module/rtl8723be/parameters/ant_sel:2
/sys/module/rtl8723be/parameters/aspm:1
/sys/module/rtl8723be/parameters/debug_level:0
/sys/module/rtl8723be/parameters/debug_mask:0
/sys/module/rtl8723be/parameters/disable_watchdog:N
/sys/module/rtl8723be/parameters/fwlps:Y
/sys/module/rtl8723be/parameters/ips:Y
/sys/module/rtl8723be/parameters/msi:N
/sys/module/rtl8723be/parameters/swenc:N
/sys/module/rtl8723be/parameters/swlps:N
parag@Notebook:~$ iwlist scan | egrep -i 'ssid|quality'
lo        Interface doesn't support scanning.

enp1s0    Interface doesn't support scanning.

4. No difference

I faced the same issue some months back and get it solved by using Wi-Fi on 5 GHz band. Basically, bluetooth uses 2.4 GHz band. If Wi-Fi also uses the same band, there will be some interference between those. So, changing the Wi-Fi to 5GHz band and using bluetooth on 2.4 GHz solves the problem.

In my case, when Wi-Fi is connected, bluetooth headset's latency was increased. And after doing some research online, I found the solution. Switching bands greatly improved things.

Hope this helps! :)

EDIT:

Info to post

Please post the following info

1. Output of commands

    $ uname -a
    $ sudo lshw -class network
    $ modinfo rtl8723be          <-- DONE
    $ ls -al /etc/pm/config.d/
    $ ls -al /etc/modprobe.d/
    $ sudo iwlist freq           <-- DONE
    $ lspci -knn | grep Net -A2  <-- DONE
    $ sudo lsmod | grep rtl8723be
    $ sudo iwconfig
    $ inxi -Fxz
   

2. Brand/model of your computer

3. Where did you see "'no network found' (Ubuntu unable to find any wifi network)" after using ant_sel=2?

Things to try

1. Setting option swlps=0 (somehow it is not set at that default as of now). Run these commands and post the output and resulting behavior.

    $ sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be swlps=0 fwlps=0"
    $ cat /etc/modprobe.d/rtl8723be.conf
    $ iwlist scan | egrep -i 'ssid|quality'
   

   Reboot

    $ cat /etc/modprobe.d/rtl8723be.conf
    $ grep [[:alnum:]] /sys/module/rtl8723be/parameters/*
    $ iwlist scan | egrep -i 'ssid|quality'
   

2. Setting option ant_sel=1. Run these commands and post the output and resulting behavior.

    $ sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=1"
    $ cat /etc/modprobe.d/rtl8723be.conf
    $ iwlist scan | egrep -i 'ssid|quality'
   

   Reboot

    $ cat /etc/modprobe.d/rtl8723be.conf
    $ grep [[:alnum:]] /sys/module/rtl8723be/parameters/*
    $ iwlist scan | egrep -i 'ssid|quality'
   

3. Setting option ant_sel=2. Run these commands and post the output and resulting behavior.

    $ sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=2"
    $ cat /etc/modprobe.d/rtl8723be.conf
    $ iwlist scan | egrep -i 'ssid|quality'
   

   Reboot

    $ cat /etc/modprobe.d/rtl8723be.conf
    $ grep [[:alnum:]] /sys/module/rtl8723be/parameters/*
    $ iwlist scan | egrep -i 'ssid|quality'
   

4. Disabling the 5GHz band in the router. Post the resulting behavior.

Notes

1. Compiling a new driver (often using a driver from Larry Finger) solved the problem for many people, but all those posts are old, so I guess it is not a problem-solver as of now. See e.g., this, this, this.

2. It seems some HP models do not have both antennas cabled, see this, this, this.

3. I would also try removing the option for coexistence, but there seems to be no option at the driver level for this. There is a dependence on btcoexist, but I wouldn't know how to use that, perhaps someone else knows.

Did it work well at any time? If so, you could try booting to an older kernel, at least to test further alternatives below.

Interference between bluetooth and wifi is well known, I am listing below a few sources, which include general methods of avoiding it.

In Ubuntu, the way to implement those methods are by setting options for the driver. Run in a terminal

$ sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=1"

and reboot. You might need/try

$ sudo modprobe -rv rtl8723be
$ sudo modprobe -v rtl8723be ant_sel=1

If that doesn't work, try with ant_sel=2. If that doesn't work either, other options may help. I don't have an rtl8723be to test, but you could post the output of

$ modinfo rtl8723be

to get a list.

Note that solutions like this (distancing bluetooth and wifi adapters), or changing the band, do not work for you, since Realtek RTL873BE is a "802.11bgn PCIe WLAN with Bluetooth 4.0 Single-Chip Controller" (single band, 2.4GHz).

Ubuntu sources:

1. Bluetooth Audio interfering with WiFi?
2. Wi-Fi connectivity issue - Ubuntu 18.04
3. Realtek RTL8723BE Wi-Fi incredibly weak
4. Realtek RTL8723be doesn't have good reception
5. Wi-Fi connectivity issue - Ubuntu 18.04
6. https://ubuntuforums.org/showthread.php?t=2384889
7. https://infinitecoder.github.io/posts/2017-12-09-rtl8723be-fix/

General sources:

1. How to Stop Bluetooth Interference From Messing With Your Other Devices
2. WiFi and Bluetooth interference – diagnosing and fixing
3. How to Avoid Bluetooth Interference in Headphones
4. https://www.quora.com/How-do-I-stop-my-bluetooth-headphones-from-interfering-with-my-WIFI-signal