I had this issue in Act 1. I just ploughed on, and the condition vanished when I moved to act 2. If you're near the end of act 2, you can possibly just carry on and see if you can shake the condition as you move on to Baldur's Gate from the Shadow Cursed Lands.

But definitely report the issue to Larian, too, if you haven't. There do seem to be a number of oddities with the way the game is handling NPCs who are designated "guards", and hopefully these will be properly fixed at some point.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"