Diamond Weapon bug

It seems that pulling Diamond Weapon with a player disconnected from the party will cause the party to be stuck in an instance until the enrage. The party cannot leave the instance as they are in combat, but the fight will continue as long as there is an "alive" disconnected player.

Date & Time: 08AUG2021
Frequency: Always?
World name: Gilgamesh
Character name: Yuai Umbralstorm
Retainer name: N/A
NPC name: N/A
Monster name: Diamond Weapon
Class/Level: 80SCH
Party or solo: Party
In-game time: 03:56PM EST
Area and coordinates: The Cloud Deck (Extreme)
Housing: N/A
Steps:
1. Have player disconnect from party
2. Engage the boss fight.
3. Wait until enrage to end the fight.