Yeah, I have the same issue only with Prophesy of Pendor as well. A guy named noosers suggested:
"You can retract the activation key from your steam license, download the last stable version from taleworlds/mbrepository and happily game away without steam.
And deactivate the dreaded auto-update function."
Not sure if it works as I haven't tried it myself. But honestly I don't want to have to do that. I bought the game on Steam for a reason, and I want to play it on Steam. If they broke it they should fix it.