I'm using 21.10 Mate on my computer (this is the first version which runs on my computer since 16.04). (7200U, onboard vga)
I'm happy with it, stable, but when i leave my computer turned on for a while and leave alone it starts to dim the screen . The dimmed screen is steady until i reboot, so i have to reboot every morning.
I cant figure out where can i disable this "feature".
The screen shots will be a little different on 20.10 but the places to adjust the power management and screen saver settings will be the same. You will need to adjust both to eliminate the dimming and/or screen saver.
The dim function is turned off in the power management menu but it does the same.
Its sure not the power management does thing, because it wont get brighter if i press a key. Just the reboot helps.