So apparently switching on Warmode works, since you go to a different instance of Skyhold which doesn’t have the bugged Valkyr.
I think you could also try having a warrior friend on a different realm go to Skyhold and invite you to their shard; that might work too. Just try anything that gets you to a different instanced version of Skyhold where the Valkyr might not be bugged.
Here’s the thread that talks about:
Hope this helps!