Bramble Valley Boss fails to despawn terrain during Maven encounter

Bug Report ID: #2376612964

Maven spawned Melur Thornmaul (harvest bear) as one of the random bosses during the first brain phase. The bear used its 'thorn corridor' attack which creates a couple of terrain objects. I killed the bear (not the brain) and though the graphic for the walls disappeared, I was still subject to its collision.

The invisible objects persisted for the rest of the fight. Maven desynced a little as well, sometimes teleporting or throwing moves a second earlier than the voice prompt. This is probably because she was colliding with the phantom objects too. She didn't spend much time in that part of the area.

Here's a video I took after the fight was over:
https://youtu.be/Wn6QQGk_c3o