I had a interesting experience last night trying to polar align my MACH1, which is portable on a tripod. After polar aligning with my RAPS, I went to check with a drift align in PHD2. I drifted in just east of the meridian and was off by a couple of arc-minutes. I adjusted to within 1 arc-minute. I then slewed to the West horizon and drifted in Az. It was apparently off by over 10 arc-minutes. I adjusted to under an error under 1 arc-minute. When I slewed back the original star I drift aligned Alt on, PHD2 said it was off by 14 arc-minutes. I then adjusted Az to get polar error under 1 arc-minute. Then using PHD2 guiding assistant, I checked the polar alignment error, which was calculated at 4.5 arc-min.
Any tips on what to check or what user errors I may have to cause an adjustment in Alt to effect alignment in Az (mount spirit level appeared level). During calibration of PHD2 I did not get any errors and I don’t think I deviated from my normal routine, which usually works well.