There are a lot of infinite battles in the game. Unkillable champs in dungeon waves, Arena healer vs. opponent that does not enough damage. It's probably not going to change.

I can't see the image, but I assume it's an arena battle against a team that your team is not able to kill.  If so, then yes this means that you will need to exit the match as you have lost the battle.  The goal of arena is to kill your opponent.