Brightness goes to minimum if I press the brightnrss control button after each boot

After the boot, the brightness is always maximum. Whenever I press brightness control button (function keys), my brightness automatically goes to minimum. Then I have to manually adjust it. It couldn't just retain the same brightness of the previous session each and every time I boot. It is happening only in the versions of ubuntu 20.04+, before that like in 18.04 or 16.04 everything was perfect.
again I had to made the wifi working each and every time I install ubuntu on this machine by editing the grub file to "quiet splash pci=realloc". The cpu is amd A6 pro 7350b.