WiFi Power Management Keeps Turning On

I needed to speed up my Wifi, so I ran sudo iwconfig wlp2s0 power off which turned off power management. To check, I ran iwconfig and it was successfully turned off. But after restarting, the power management was back on! Why does it turn back on when I specifically turned it off?

It also turns back on when I unplug the charger and such.

Here's the output of iwconfig:

lo        no wireless extensions.

enp1s0    no wireless extensions.

wlp2s0    IEEE 802.11  ESSID:"Fullam-2.4G"  
          Mode:Managed  Frequency:5.745 GHz  Access Point: 76:AC:B9:10:0B:5C   
          Bit Rate=6 Mb/s   Tx-Power=30 dBm   
          Retry short limit:7   RTS thr:off   Fragment thr:off
          Power Management:on
          Link Quality=35/70  Signal level=-75 dBm  
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:36   Missed beacon:0

How do I make power management stay off?

Try editing /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf and changing the 3 to a 2 (make it look like the following):

[connection]
wifi.powersave = 2

Reboot.

Please try:

sudo sed -i 's/3/2/' /etc/NetworkManager/conf.d/*   

Reboot and check:

iwconfig

EDIT: This is highly experimental. I have not seen this on AU before and you will be testing it for us! If it is not successful, it can be reverted in one command:

Please do:

sudo apt update
sudo apt install tlp
sudo nano /etc/tlp.conf

Change these lines:

# WiFi power saving mode: on=enable, off=disable; not supported by all adapters.
#WIFI_PWR_ON_AC=off
#WIFI_PWR_ON_BAT=on

...to read:

# WiFi power saving mode: on=enable, off=disable; not supported by all adapters.
WIFI_PWR_ON_AC=off
WIFI_PWR_ON_BAT=off

Save (Ctrl+o followed by Enter) and exit (Ctrl+x followed by Enter). Next, do:

sudo tlp start

Confirm that the settings are active, run the following command:

tlp-stat --rfkill

You should see Power Management = off.

EDIT 2: I suggest that you try another method. Please open a terminal and do:

printf '%s\n' '#!/bin/bash' 'exit 0' | sudo tee -a /etc/rc.local
sudo chmod +x /etc/rc.local
sudo nano /etc/systemd/system/rc-local.service

Add the following:

[Unit]
 Description=/etc/rc.local Compatibility
 ConditionPathExists=/etc/rc.local

[Service]
 Type=forking
 ExecStart=/etc/rc.local start
 TimeoutSec=0
 StandardOutput=tty
 RemainAfterExit=yes
 SysVStartPriority=99

[Install]
 WantedBy=multi-user.target

Proofread carefully. Save and exit nano.

sudo systemctl enable rc-local
sudo systemctl start rc-local
sudo systemctl status rc-local

If all is correct, it should report that it is active. Next, do:

sudo nano /etc/rc.local

Above the line 'exit 0' add the following:

/usr/sbin/iwconfig wlp2s0 power off 

Proofread carefully. Save and exit nano.

Is there any improvement?