There was an issue for @freaktechnik a while ago, where there ended up being multiple instances of Rockons in the database causing issues. Not sure, whether the outcome of using watchtower on multi-docker Rockons could cause something similar:
If your theory is correct, then it could be that Watchtower gets confused, updating only some of the multi-container pieces and not other, and not cleaning up correctly, resulting in some duplication.
May be when you are back home, you can remove/reinstall the multi-docker Rockon(s) (I hope, you don’t have too many) and see whether that addresses the problem, using:
cd /opt/rockstor
$ poetry run delete-rockon <rockon name - case-sensitive>