Suite is running but

I see a lot of my suite jobs either running or in the queue. If I start gcylc and select File->open suite I get a list of all my suites but no host:port is listed and I cannot connect to them.
If I try to connect one I see a message "stopped with running"
Is my suite lost?

I was able to restart cylc but I couldn’t figure out why it stopped so that I could possibly prevent that happening again.

If cylc shut the suite down for any reason (as opposed to the process somehow just being killed) then there should be evidence in the cylc log file (log/suite/log).