Stuck in map. Which option do I have other than purposely fail the map to be able to continue?

I am stuck in map. I have just killed the map boss. But I can't get out of the area I killed the boss in. (on the other side of the area I see the "arena"-entrance sign. Its not "clickable"). I am locked in. The passage way is blocked by this "red somewhat obscured line" stopping me from going back to kill the rest of the mini-bosses. If I portal back out and in, out and in... at the end I will get the map as failed since there still is mobs I need to kill. What shall I do? Only option is to on purpose fail the map to be able continue playing or if by a miracle some devs can get in-game and fix it asap.