After recreating a folder as groupfolder, the original (removed) folder gets synced back every odd hours

As groupfolders offer more flexibility on permissions we removed a classic folder and created a groupfolder with the same name.
Now the original (and now empty) folder gets recreated every few hours with an attached counter (x).
Does anybody know

  • where it comes from
  • how to stop this?

As the documents and files in this folder are dependent on the path and moving them out into another folder is not an option, I’d appreciate a solution to stop the replication.