Steering angle needs to see 4 equal speeds from each wheel. I have seen many times the rear right wheel fluctuates in speed and it is nearly always the bearing with the exciter ring.
Go in to 03-ABS and get all 4 wheel speeds up in Measured Value Blocks - 001 and just go in a straight line (don't have to go fast, 5-10mph is fine) and see if they all match, you might find one fluctuates hence why your steering angle fault won't go away.
May be wrong, but seen this many times and nearly always rear right bearing for some reason.