We faced unexpected behavior (the trigger has been run too many times -every 30 minutes- Although there is no new transaction item added to the queue.) with the Queue Triggers after investigation, we found a stuck items on InProgress status, after reading the documentation , we found the justification below
Orchestrator takes into account both New and In Progress queue items when computing the number of target jobs that must be reached for optimal resource allocation.
I think if you can add an attribute to the queue trigger creation page to choose the transaction status eg: new or InProgress or both (For example, find the below image).
UiPath Orchestrator: Enterprise on-premise 21.10.1
Minimum number of items to trigger the first job: 2 items
Maximum number of pending and running jobs allowed simultaneously: 1 job
Appreciate your feedback regarding this.