Same for me, except Lohse is my main avatar character so I cannot progress (at around 22+ hours in). I have to admit I realised this around 12 hours in however I thought the problem might just fix itself somehow! This occured to me after the first time I performed the ritual and teleported out of the hall of echoes or whatever and then I proceeded to go around as my other party members for a while and realised Lohse was invincible and could fight outside of battle so I used this to my advantage as the difficulty in this game is crazy!
I didn't make a save for a few hours before it happened so it is pretty frustrating to reload back to basically just after escaping the fort! I've realised the extent of the glitch in that basically Lohse can interact with a few objects (such as levers, looting enemies!) however cannot interact with objects for the main story (such as inhaling the blackroot smoke for the second time ritual) not being able to talk with party members, NPC's and certain dialogue situations means I cannot complete the main story.
If there is a console command to autokill lohse somehow, and then ressurect with a scroll it might reset the character? I have yet to find a way to do this as well.
