Fetching is allowed. But not posting everywhere. You have to check the community id of the post / community and only respond to the wanted communities
Hmm, this is library breaking (pylemmy). I’ve tried the same code with no changes on lemm.ee and it’s working fine, so is this something that can be reconsidered at lemmy.world I wonder? I’m not sure if it has been done to combat abusive actors, but if so then I imagine a bad actor could just achieve the same thing through activitypub on a less tightly controlled instance.