i noticed i cant downvote on main AI instances anymore recently.

If all you ever did was to downvote content, maybe the mods did indeed ban you. We had a discussion recently on !fedigrow@lemm.ee on what to do in such situations.

I never say anything, never comment.

Seems like it

The Reddit ones

I started doing this myself on !Football@lemm.ee and !pokemon@lemm.ee

• !newcommunities@lemmy.world
• !trendingcommunities@feddit.nl
• !communities@ponder.cat

From those 3 you can discover others