I experience something similar, though I have never associated it with digging. I don't use Ctrl-S to stop digging, I just get up and run (often after mashing an aura button). I haven't yet been able to narrow down when it happens, but it very well could be related to digging.
I almost exclusively use the mouse to steer my character. Sometimes, I have noticed that attempting to turn the character and the camera at the same time (hold right mouse button and move the camera), my character does not turn until starting to move forward. This sounds very similar to what you describe.
I almost exclusively use the mouse to steer my character. Sometimes, I have noticed that attempting to turn the character and the camera at the same time (hold right mouse button and move the camera), my character does not turn until starting to move forward. This sounds very similar to what you describe.