I've noticed that the label features do not function properly on the Cloudron app for Vikunja.
1st error: The label continuously adds itself to the task it was assigned too. Every time the homepage is visited or the list page is refreshed, the label on the task is duplicated.
2nd error: If the label is deleted, it still remains in the list and on the task.
I did hit up the developers and everything on their end is working fine. They were not able to reproduce the issue. So, I'm assuming there might be something wrong with the app's package.