Had a brief opportunity to test today.
I can confirm that the yaw freeze occurs even WITHOUT a phone connected and GO4 running - controller only. It also occurs on either direction of rotation.
This fault is quite intermittent. Could I ask people who have not seen it before/yet to try a quick test - something to do once you are home and have a bit of battery life spare. Hover about 3 meters up and 3 meters away, then apply a constant, slow yaw deflection in either direction. You probably need to watch the screen, not the drone, to spot the issue. It could take anything up to 10 rotations to see it, or it might happen straight away. It’s not the sort of maneuver that everyone will do regularly, if at all, so maybe it’s more common than people think.
Still to try - Sports mode, obstacle detection off, recheck Cinematic and Tripod mode - any other suggestions?