Rotator issues

I seem to be having trouble understanding the correct setting to use the “manual rotator” I initially took a series of images of M31 and then used 1 of those images several days later as the reference image. I cant seems to get the correct rotation set for the new image. I followed the manual promps during the centering routine as the sequence starts but the image is not in the right orientation. I think it maybe fliped 180 depending on what side of the meridian I’m at. Is that correct? But I keep getting the image set wrong even if I flip it.