In the snowy mountain you enter right after waking up due to Tristan finding you, I accidentally ran from a trainer battle thinking it was a wild encounter, so I was teleported to the healing camp right next to the staircase. When I got back into the mountain, Tristan was no where to be found. So after soloing double battles, I got to the part with the ice puzzle, and Tristan's dialogue shows up, but he's still not there (pokemon are not healed, can't interact with him, etc.)
EDIT: Nevermind, he was back at the beginning
