So I was in the queue tonight for MM dungeons. Over the course of about 5 minutes, people kept on declining the queue and it kept placing me back into the top. Then after that observed 5 minutes had elapsed, I found myself suddenly no longer queued at all.

This is very very aggravating to find myself ejected from the queue simply if others reject enough to result in the game timing me out, with no recourse on my part. Unless I cancel the queue myself, I should never be removed from it.