Slow Painful WiFi speed Ubuntu

I dual booted Ubuntu 18.04.5 with Windows 10 Pro 21h1.

In windows and all other devices I'm getting 50 Mbps but when I use Ubuntu 18.04.5 I get 1Mbps max. In WiFi settings it displays link speed as same.

Here are the configs

wlp3s0    IEEE 802.11  ESSID:"SSID"  
      Mode:Managed  Frequency:2.432 GHz  Access Point: 00:00:00:00:00   
      Bit Rate=1 Mb/s   Tx-Power=20 dBm   
      Retry short limit:7   RTS thr:off   Fragment thr:off
      Power Management:off
      Link Quality=51/70  Signal level=-59 dBm  
      Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
      Tx excessive retries:0  Invalid misc:27   Missed beacon:0

Look at the BitRate here.

*-network
   description: Wireless interface
   product: QCA9377 802.11ac Wireless Network Adapter
   vendor: Qualcomm Atheros
   physical id: 0
   bus info: pci@0000:03:00.0
   logical name: wlp3s0
   version: 31
   serial: 00:00:00:00:00:00
   width: 64 bits
   clock: 33MHz
   capabilities: bus_master cap_list ethernet physical wireless
   configuration: broadcast=yes driver=ath10k_pci driverversion=5.4.0-81-generic firmware=WLAN.TF.2.1-00021-QCARMSWP-1 ip=xxx.xxx.xxx.xx latency=0 link=yes multicast=yes wireless=IEEE 802.11
   resources: irq:131 memory:b4000000-b41fffff

It gives okay speed with mobile hotspot but behaves like a snail with WiFi router only.

I turned off the power management for the wlp3s0.

I found something in /etc/modprobe.d/blacklist-ath_pci.conf saying

# For some Atheros 5K RF MACs, the madwifi driver loads buts fails to
# correctly initialize the hardware, leaving it in a state from
# which ath5k cannot recover. To prevent this condition, stop
# madwifi from loading by default. Use Jockey to select one driver
# or the other. (Ubuntu: #315056, #323830)
blacklist ath_pci

I can sense some problem with the iwlwifi.conf as well but as much as I understand it's a driver for Intel hardware but my WiFi is Qualcomm so I don't know what that have to do with it.

I have tried several others remedies which Google and Youtube offers but the Bit Rate remains the same as 1 Mb/s.

Any Help would be appreciated.

edit 1.0 : My phone supports enabling WiFi and Hotspot at the same time so I connect my phone to the router and Ubuntu machine to the phone's hotspot. It lead to getting 20Mbps on Ubuntu Machine. (It's link speed still shows 1 Mbps anyhow). However the router to Ubuntu Machine speed is 0.25-1.0 Mbps.

This card is notorious for it's sluggishness. There is a 3rd-party firmware available if you'd like to give it a try, though.

Here's how to install it:

0. Open Terminal (if it's not already open)
1. Go to the firmware directory for the card:

   cd /lib/firmware/ath10k/QCA9377/hw1.0/
   

2. Rename two existing files (so they're not lost)

   sudo mv firmware-5.bin firmware-5.bin.orig
   sudo mv firmware-6.bin firmware-6.bin.orig
   

3. Get the 3rd-party firmware:

   sudo wget "https://github.com/kvalo/ath10k-firmware/blob/master/QCA9377/hw1.0/CNSS.TF.1.0/firmware-5.bin_CNSS.TF.1.0-00267-QCATFSWPZ-1?raw=true" -O firmware-5.bin
   

4. Reload the kernel module:

   sudo modprobe -r ath10k_pci
   sudo modprobe ath10k_pci 
   sudo dmesg | grep ath10k
   

That should give you proper transmission speeds.

Check your WiFi MTU, using

ip link

or

ip l | grep $(ip r | awk '/default/ {print $5}' ) | awk '{print $2, $4, $5}'

also notice your WiFi interface's name.

The MTU (Maximum Transmission Unit) is the size of the largest packet that can be sent in a single network transmission. If a packet exceeds the MTU of a link, the data must be split into multiple packets (fragmented). These multiple packets must be sent over the link, received, acknowledged, and reassembled at the far end. If your link is misconfigured, and you have to fragment every packet you send, your actual data transfer rate drops.

Ethernet (wired) networks use an MTU of 1500 bytes.

Due to additional per packet overhead for WiFi (8 bytes PPPoE header), WiFi uses an MTU of 1492.

Your MTU should be set by your DHCP server, check your router's config.

You can set your own MTU (setting does not persist over restarts) with

sudo ip link set dev name mtu 1492

where "name" is the interface name from above.

Here's an example:

walt@squid:~(0)$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp63s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:24:21:7f:e5:1c brd ff:ff:ff:ff:ff:ff
3: wlxf46d04b1790f: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DORMANT group default qlen 1000
    link/ether f4:6d:04:b1:79:0f brd ff:ff:ff:ff:ff:ff
walt@squid:~(0)$   sudo ip link set dev wlxf46d04b1790f mtu 1492
[sudo] password for walt: 
walt@squid:~(0)$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp63s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:24:21:7f:e5:1c brd ff:ff:ff:ff:ff:ff
3: wlxf46d04b1790f: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 qdisc mq state UP mode DORMANT group default qlen 1000
    link/ether f4:6d:04:b1:79:0f brd ff:ff:ff:ff:ff:ff

My WiFi "interface name" is "wlxf46d04b1790f".