Reproduction:

	
Have a job that's triggered repeatedly by a timer.
	
make sure there is no node to execute that job.
	
Let the job sit in the build queue for some time.



Result: After some time the build queue hover of that stuck job might take up all visible space, because it contains all the failed time based triggers:



I suggest to remove all duplicate build causes (or whatever model elements those are), as they don't provide any benefit for the user.