Schrodinger's Pipline

Pipeline both fails and succeeds

I ran a CICD pipeline last night (one we run regularly), and for the first time the final deployment stage failed with a timeout:

There has been a timeout failure or the job got stuck. Check your timeout limits or try again

When I look at the logs for the stage I see the very last few lines are:
Cleaning up file based variables
00:01
Job succeeded

When I look at the information about the stage, I see:
Duration: 110 minutes 33 seconds
Timeout: 1h (from project)

This deploy stage usually takes between one and two minutes, not an hour!

It seems maybe the job completed successfully (the new build seems fine) and then stalled after the Job succeeded message for over an hour until the pipeline timed out. Seeing as I just bought Pipeline minutes for the first time last week, I am not happy about this!