When Watcher is upgraded to 7.16 it is possible that during the rolling upgrade Watcher gets stopped on the elder nodes and will not function until all the nodes are fully upgraded. There is a specific order of events that must happen for this bug to present itself (sometimes it works fine but other times it can stop Watcher) and once fully upgraded Watcher should be fully functional.

This bug was discovered via the rolling upgrade tests and additional information can be found #81110 (comment)

Related: #80937