Boss Akthi, the Final Sting disappears and becomes invulnerable during fight

Bug Report ID: #1488541971

Description:
During the Interlude in the Khari Crossing map, the boss Akthi, the Final Sting bugged during the encounter.

While fighting the boss, Akthi suddenly disappeared mid-fight. After some time, the boss reappeared, but remained completely stationary, not performing attacks or mechanics as expected.

Additionally, after returning, the boss was taking little to almost no damage, making the encounter behave incorrectly and breaking the fight flow. The boss did not reset properly nor resume normal behavior.

This issue occurred during normal gameplay and was not related to player death or instance reset.