Server showing possibly aborted

I’m pretty new to HangFire and I am looking at a system where the server shows a red triangle and says “Possibly aborted”. The server seemed to get stuck processing some jobs so we manually requeued them and then processing started to happen.

I cleared out all the queues and restarted the server and now jobs are processing correctly, but the server shows this warning.
From what I can tell, the server is alive and working. Why does it say 4 hours since the last heartbeat?

Please advise. Thanks!