Maven's arena bug

During the fight with normal maven, i got stuck on the invisible wall across half of the arena. The reason for this might be some kind of boss that spawns during the brain phase. During the fight the red harvest bear has spawned, and most likely did an attack which spawns a wall, and the collision of the wall just stayed there forever without a texture.

Same has happend to me. Purple harvest bear spawns the tunnel which it charges through. Brain died and the wall is rendered invisible but still on the arena as impassable invisible walls.