Elder guardian not creating portal in Mirage

It seems that elder guardian fight is bugged in Mirage. After defeating the fight there is no portal to return back to map and the only way to get out of this is to log out. I created a bug report using the /bug command in game, the ref no is 843 458 934.
For me this happens every time when doing the Mirage version of the fight, the normal fight works as expected. Note: Only testing this in City Square map.

Edit: F7 (teleporting to Mirage portal) still works, so escape is possible :). By the way, Awesome league guys, thank you!