Hello @sebasb, and welcome!
I unfortunately have had that happened to me once with a container getting stuck in a transition state. As you wanted to uninstall this Rock-on anyway, the best solution in this case is to simply use a script that we have to do just that. It is described in several other threads on this forum, but its usage is as below:
Please note that the Rock-on name is case-sensitive.
This script will uninstall the container (if not done already) and also remove its entries in Rockstor’s database. That should fix your issue.
Hope this helps,