Date & Time: 10/23/2022, tested throughout the day
Frequency: Always
World name: Behemoth (also replicated when visiting Excalibur)
Character name: Scarlet Jackal
Retainer name: n/a
NPC name: n/a
Monster name: Luminion, Drifting Ea, Level Tricker, Arch-Eta, etc (any enemy in Ultima Thule, even FATE ones and A rank hunts)
Class/Level: Fisher/Botanist/Miner, level 90
Party or solo: solo
In-game time: various
Area and coordinates: Ultima Thule
Housing: n/a

Steps:
1. Go to Ultima Thule
2. Change into a DoL class, any of them
3. Make sure Sneak is active
4. Use the aetheryte to change into a different instance than the one you are currently in
5. Approach any enemy in the zone
6. Despite Sneak still being active on the character, the enemies aggro and attack your character and the Sneak status falls off

This seems to be an issue only when you have Sneak active and then change instances; if you change instance and then change into a DoL class, or toggle off and then retoggle Sneak after changing instances, this bug does not occur.