Hey there. Are you referring to the various reports you've sent the other day for [email protected] or did you find other posts / other communities with the same issue?
Your reports got noticed by Unruffled (lemmy.dbzer0 admin) and we are currently trying to troubleshoot it in the admin Matrix chatroom. Long story short, there seems to be a problem with mod actions not federating correctly / not getting re-attempted after failures. And while the problem was first discovered on our instance - thanks to your reports - we aren't the only instance affected by this.
The sad truth is that Federation is a bit wonky and at times things like this happen. The problem with these issues is that they are super hard to replicate and thus identify. The next update is set to improve it, hopefully it will solve this mod action issue too.
EDIT: an issue got filed on GitHub, you can track it here: https://github.com/LemmyNet/lemmy/issues/3980