Destructive Play - Mesa bugged

I have the maven keystone enabled - Destructive Play

In Mesa Map, Maven does not appear nor does she spawn the extra monsters.

(I did not have mesa witnessed already, want to highlight that before it is suggested + on the bottom right I got a notification output saying Mesa witnessed by Maven)

Bug report: 3 785 303 148

Voidstones: 4
Keystone: Destructive Play
Map: Mesa
Steps to reproduce: Open Mesa Map which hasn't been witnessed, go to the boss area and kill the boss. You will notice no extra bosses spawned + Maven does not cast anything else nor does she appear while fighting the boss)

Edit, once you kill the boss and go out, she appears. but the extra bosses didn't seem to drop anything. This is still considered a bug as they should spawn within the boss area, not outside it, looks like a placement issue