Stun/Stagger Bar Not Interrupting Boss Actions Properly

I want to report an issue with the Stun/Stagger mechanic in Path of Exile 2, which I have observed on multiple bosses.

Issue Description:

-The Stun/Stagger bar (horizontal bar below the boss health bar) is intended to interrupt the boss immediately and prevent actions once it is full.
-During the campaign boss Balbala’s camouflage phase, she becomes invisible and untargetable until the player locates her in the arena. This phase makes the issue particularly noticeable.
-If the Stun/Stagger bar fills just before this phase, the boss should be staggered or interrupted immediately, preventing all actions.

Observed Behavior:
-Balbala becomes invisible and must be searched for by the player.
-After she is found, she “reactivates” and performs actions.
-While the Stun/Stagger bar is draining, she continues to act normally, and only after the bar finishes draining does she enter a very brief stun, not corresponding to the expected immediate interruption.
-Similar behavior has been observed with other bosses, suggesting this may be a systemic problem with the Stun/Stagger mechanic.
-It appears the boss continues actions during certain phases even when the Stun/Stagger bar is full, suggesting a priority or timing issue between boss phases/animations and the stagger mechanic.

Impact:

This makes the Stun/Stagger mechanic unreliable and can mislead players about boss control windows, especially during longer phases.