Hi McGherkin!
Haven't seen you around in a while, nice to see you back.
This can happen sometimes, when the server collects too many bugs, I find. When that starts happening, you know it's time to re-start the server, if you're the one running it, or, contact the person who is running it and tell them what is happening, and that the server should be re-started.
Although, more often than not, I find that running just the one server makes for better results, as well as not putting too many boats/ships on the list.
Hope that helps.
Kind Regards,
Jack