AoE abilities only affect single target NMs in "The Seagull Phratrie" mission

Platform: Windows 10
ISP: ATT U-verse
Type of Internet Connection: Broadband
Internet Connection Speed: 50 Mbps
Date & Time: Oct. 16, 2021 about 00:35 CDT
Frequency: Once
Character Name: Edyth
Race: HumeF
World: Asura
Main Job: SMN, Lv.99
Support Job: WHM
Area and Coordinates: Arrapago Reef, K-7
Party or Solo: Party with 5 trusts
NPC Name: None
Monster Name: Merrow Kabukidancers, Qutrub, Mamool Ja Divers
Steps:
1. Spawn the NMS for the Voracious Resurgence Quest, "The Seagull Phratrie"
2. Attempt to AoE stun them with "Shock Squall," but it only affects one target due to this AoE glitch that has been discussed by other players
3. Die because no SMN can survive tanking 5 NMs

Note: I corrected the zone info! It was Arrapago Reef, not Caedarva Mire