Sounds like your instance have federation issue, probably due to v0.19.0 updates. The latest version, v0.19.1, supposed to fix those federation issues. Not sure what's the server specs of your instance, but v0.19.x has increased database ram usage compared to previous versions, so if the instance is hosted on a tiny server, the admin may need to do some tinkering to make sure the federation process doesn't crash due to out-of-memory issue.
Unfortunately, seems like 0.19.1 didn't fix it. I still have issues on some instances and posts. There is still something wrong with federation. Hope it gets fixed soon.