Encounters (BoT): 25HC Cho'gall encounter not ending properly, Sinestra encounter unable to start

[mrlamp339]

Description:

The Cho'gall (NPC ID 43324) encounter does not end properly. Before the latest commit in the past few days, upon reaching 2% HP Cho'gall would slowly walk to the center of the room and break the floor, as he is supposed to, but did not die. He would fall to the Sinestra (NPC ID 45213) room but infinitely walk slowly unless you used the .die command. Now, he does not do this, stated below.
Sinestra is currently unable to be started at all, as you cannot reach her room since Cho'gall does not break the floor. Before the latest commit though, you were able to reach her room, but she was unattackable, with the NPC Calen (NPC ID 46277) currently present before the encounter, which he is not supposed to be there beforehand. So, the Sinestra encounter cannot be started.

Current behaviour:

Upon reaching 1 HP, Cho'gall sits in place attacking the player and does not die.
(Before latest commit when she was reachable) Sinestra is present in her boss arena but is unattackable, along with the NPC Calen standing there before the encounter casting an invisible Flame Shield.
Now, she cannot be reached at all due to Cho'gall not breaking the floor upon 2% HP.

Expected behaviour:

When Cho'gall reaches 2% HP, he should slowly walk to the center of the boss room and break the floor & die simultaneously. This floor break enables players to fall down and reach Sinestra. Cho'galls death triggers the Sinestra spawn, where she should be residing in the lava beforehand, then she comes up out of it shortly after you reach downstairs.
Sinestra should be attackable after her spawn to trigger encounter start. Calen NPC should not appear until P2 of her encounter.

Steps to reproduce the problem:

1. Clear the first 3 bosses of the instance.
2. https://www.wowhead.com/npc=43324/chogall , Bring Cho'gall down to 2% HP, watch as he sits there and does not die.
3. (Before latest commit) https://www.wowhead.com/npc=45213/sinestra , Unattackable and unable to start the encounter

TC rev. hash/commit:

TrinityCore rev. 7316f67 2023-12-24 05:57:28 +0100 (master branch) (Win64, RelWithDebInfo, Static) (bnetserver)

TDB version: TBD 434.22011

Operating system: Windows 11

Cho'gall video
https://github.com/The-Cataclysm-Preservation-Project/TrinityCore/assets/46968850/59e7255b-7462-489f-8d25-103049df0a03