if no one on your home instance was subscribed to the community, it wont get posts or comments. the first time someone on an instance searches the community it seems to just get a few of the old posts but it doesnt get their comments; if you or someone else on your instance subscribes then the instance will get new posts and new comments
0.18.3 is bringing in more sanitization, probably got missed.
I poked them and they’re working on a fix