Known issue.
April 16th's patch was set to make Pantheon mainly focus on 2v2 games as a temp fix. The negative side effect is that the game keeps wanting to make 2v2 matches, which means Crucible is the ideal. The ETA on when this patchwork repair will be lifted with a real fix has not been determined, but Stardock knows of its existance is working on it.
As they said, "It's better to be playing on Crucible than not be playing at all."
