Okay, so 11/29/21 camped the froglok shin lord @ /loc -12.08, 275.64, -94.84 with my 75 sk. Cleared the room and approx 13 - 15mins later the froglok shin lord pops on top of me with Ghoulbane. That was after the first time I cleared the room. I don't really know if they changed spawn rates or rarity of his spawn or whatever. Maybe I was lucky or maybe they changed it. With Brewall's maps the spawn location is shown in the far Southwest corner of Upper Guk.
Good luck.
Gravelord Caikalyn Korabynn