There may possibly be some issue with outgoing federation as noticed by this commenter: https://lemmy.ml/comment/6690834
In fact, it seems comments from lemmy.ml haven’t been federating since 4 days ago. Just check some active lemmy.ml accounts.
e.g.:
https://lemmy.ml/u/dessalines?page=1&sort=New&view=Comments
https://lemmy.dbzer0.com/u/dessalines@lemmy.ml?page=1&sort=New&view=Comments
I am not entirely sure if it’s something to do with 0.19, but my home instance, lemmy.sdf.org is also having issues with outgoing federation since upgrading to 0.19.x, although it’s currently still just on 0.19.0-rc.13. That’s also why I am writing this from this account instead.
*for when
But yeah, this is it.