installed f36 on my MSI Modern Bm4w laptop with ryzen 5 4000 series chip and AMD Radeon graphics card. for some reason, the screen brightness changes itself randomly from time to time even tho I’m not even touching the computer.
My experience (with an HP laptop using AMD Ryzen and Radeon) is similar to yours. I haven’t experienced random changes in brightness while it’s running, but the brightness on booting DOES seem to be random.
There’s nothing like that going on on my DELL laptop w/Intel.
Same for me on a Microsoft Surface Go 2.