On Rustbowl not able to leave Boss Arena

So I was just playing the Map Rustbowl and after i Killed the Boss i was stuck in the Boss Arena and not able to leave.

I was blocked by the "Arena" Gates and couldn't go out anymore.

Maybe this Problem can occur on more Maps, it happened to me on Rustbowl for the first time.

https://imgur.com/vzMtmoK

I was blocked too. While moving on the map the boss has been appeared in its own special area. After I killed it, the "arena" doors had been locked.

I've had this happen to me twice. It's to the point now that I do the arena part last just in case I get locked inside it.