We have users trying to sync roadmap and it keep on spinning. It has been about an hour and still going.
Clarity 16.x
Roadmap Items Sync internal job was stuck in Processing status and when other users attempted to sync other roadmap they were getting stuck in Waiting.
There was a lock under security.locks page for one of the roadmaps which we had to clear to allow Roadmap sync job to finish.
Locks can happen when another process interferes with OOTB Roadmap sync. It is possible that this lock will stay because that action could not successfully finish what it started to do and there is no time out when it comes to lock as those stay in the table and can only be cleared by the action itself or via security.locks page.