I have gotten this behavior with both Viconia as well as a few CM Partners companions.
At some stage I summon them, and they show up as a frozen/paralized and then gently tip over, stiff as a board.
They respond to to talking but they can't actually move.
I suspect it has to do with something happening to them in a combat, where I lost track of them, and then when I summon them, that effect is in place and won't go away.
I have tried console commands like kill/resurrect, enable/disable, dispellallspells, but nothing seems to work.
Any ideas?
Thanks,
Michi