(singleplayer, testlive 2.6b, no mods)
Inside the room with the Warmaker’s Adjutant player gets stopped by an invisible piece of terrain/decor.
(Enter Warmaker’s Sanctuary, go through door at end of first section and into the room with the map. Turn left and go through the first of the doors - through this initial section and into the room with the miniboss.)
In this screenshot, the character (back to camera) is jammed right up against the edge of an invisible obstacle and cannot move further forward (thrall has maybe half a metre between him and his side of the obstacle):
To clarify the location, the following is taken from just inside the door to enter that chamber - the invisible blockage is ringed in red:
There is a matching brazier on the other side of the room, which has a similar problem, but the invisible block only extends about half as far into the room.