There are lots of instances proactively blocking bad instances (hate speech, racism, spam,...) which is good but sometimes they overdo it by blocking instances just because of some minor, redeemable mistakes from their admins or users; or because of incompatible views despite they haven't done anything wrong.
Sometimes they even do the point that can be considered harassment towards that admin/mod/user as well.
Mastodon convenent should be updated now.