Please tell us some basic information before asking for help:
Can anyone else confirm that they are also having this issue?
It is normal for me to change the brightness on the lock screen.
Clear cache and storage of Asus launcher
Settings >apps & notifications >see all apps > Asus launcher > storage > clear cache/clear storage!/Force stop > now u can check again if beaviour is same.
I tried on the live wallpaper and it's normal for live wallpaper but tried still wallpapers afterwords... It's still the same.
I tried to change to still wallpapers, and I saw the problem you mentioned. Is it normal before updating to .90?
Yes it was normal before .90 update.
Thanks for the suggestion but it didn't work...
I have reported this problem. If you care about this issue, please use live wallpapers for now.
I don't care... I just wanna check before reporting 😅
Thanks for reporting the same has been highlighted ahead.