Cannot leave arena after killing map boss

This happens on different maps, not just one. I enter boss arena, kill the boss, but the red wall is blocking exit so I cannot leave. In regular maps, if I have more than one portal left, I can relogin to hideout and portal back to map out of boss arena, but if the map requires quest item to progress (for example: Castaway), it cannot be completed at all because quest item is dropped on boss arena which is locked. This happens every 10-ish map.

Bug Report ID: #2781550596