So trying to diagnose the issue, it seems there are spam spikes from outside of our server, but in trying to federate with these events, it starts running our CPU of the server at 100% and errors out. When I restart it during that, it seems to have issues and I have to rollback.
Thankfully, we had a rollback from last night this time, but for now that means I will be removing the largest non-art communities that would get spammed, such as memes, news, and politics from the large big servers. This means that this instance will probably be more useful just for art only for the time being. Many mobile clients allow you to login to multiple accounts on different servers, so you may need to do that to get better access to non-niche content.
There will be an eventual lemmy update that will create a federation queue that addresses this, but for now, we have to work with what we have.