I'm sure this is already well known, and I have submitted an ingame bug report already. but I thought I'd post here too.
The issue: Tuxartis and Grasuul are rarely in the tower when I zone in. It might just be me and my RNG luck, I typically zone in and their rooms are empty.
The current remedy: I log out and back in... sometimes over 30 times before they pop into existence. It doesnt matter time of day from what I can tell. Sometimes I'm lucky and first relogging of my char gets them to load, but honestly I'd say I average 10-20 minutes of constant relogging on average to get them to show.
I'm curious if others have a trick to correct this in the mean time as well!
Thanks!