I really have no idea why I was banned from those two communities specifically. I don’t think I’ve interacted with any of them (apart from reading/voting) for weeks. It’s not an instance ban.
If there is a better place to post this, please tell me.
EDIT:
I posted a link that was falsely flagged as malicious, have been unbanned! See comments for more details!
Some users would get into arguments with some, then show screenshots of recent bans (from communities the other user never even posted in) and say, “See? You’re a troll! Look ya just got banned!!”
I don’t think people should be allowed to be banned from communities that they’ve never posted in just for that reason.