[Lapis Manalis] Hydrofall stack marker not working correctly with NPC's

Date & Time: 1/13/2023 @ 10:45AM
World name: Jenova
Character name: Mjrsa Zhel
Monster name: Cagnazzo
Class/Level: Samurai/Lvl 90
Party or solo: Solo with NPC's
Area and coordinates: Lapis Manalis

When Cagnazzo casts Hydrofall, the NPC's(Alphinaud, Varshahn, Y'shtola) gather around to share the damage from the stack marker. Anytime I share the damage with them, I take the full damage and die, preventing me from completing the dungeon. I have replicated this 3 different times.