Lemmy.ca's Main Community

I've found this in particular with lemmy.world with posts made on lemmy.ml communities, which seems to be the case in your example as well (the community you posted to is ThinkPad@lemmy.ml).

Lemmy.world has been defederated in at least one high profile case. ~~I have a suspicion .ml may have defederated as well without announcing (unless maybe we have defederated them here @lemmy.ca? Still working out how source of truth works myself).~~ edit: checked, both still list .world as linked

If an instance defederates another it means they will not accept engagement from that instance. However, if that instance does not reciprocate the defederation they still get a copy, and it is isolated to their instance. Ie. Comments/votes only appear on that instance and the instances they federate with.

Not entirely sure though as I would think that means lemmy.world would still receive edit/deletion broadcasts which it doesn't from my experience. So maybe just a bug.

Basically, at least from my experiments, Lemmy.world gets the original post / comment, and all engagement on the lemmy.world instance stays isolated there (lemmy.world has a large user base therefore often more engagement).

This is going to be an ongoing problem for folks because there really isn't a way to see who (instance) is talking to who (instance) (edit: incorrect; a user pointed out a place to check, but it isn't always going to be clear unless you constantly check). Without a platform wide policy of mutual, reciprocal defederation, there is going to be a lot of fractured discussion users will never be notified of.

*edit: may not be an issue with defed. See comment below.