Apologies if I did not pick the correct component for this, please change to the correct one if needed.
When using Polling instead of build requests from Bitbucket, business environment requirement, Jenkins will add repeated multibranch scans to the job queue even when one is already queued. This occurs because Bitbucket cloud has limitations on API use so if enough requests come in the queue gets back logged.
Jenkins should not be adding requests for multibranch scans to the queue if one already exists for that job. Since the scan only uses one executor on the main server this causes the queue to fill up and slow builds down dramatically.