Very nice shooting there Dave. I'm not sure why the sights do that after an adjustment. I've had a couple rifles do that to me also.
Maybe you could possibly be canting the rifle slightly. Try cranking down the sight and see if it shoots low left. Or move it down where it was and set the front sight a little higher in the rear sight "U". If you're canting the rifle a bit both methods should move the POI horizontally.
That little bit of movement would only take a couple degrees of cant.