AZ-EQ6 driving off on its own while guiding

Hi,
I have had similar issues with the EQ8. (Read a previous post)

How much does it move over time? I have drift in the original coordinates I have set after each sub.

I read in the fits headers, the RA and Dec coordinates, after each sub and they are different.
Is this normal? I thought once you set the RA and DEC it should be the same.
Except for small dithers, which, I set at 2 pixels every 5 frames.

After an hour, I will have to re-centre the object. I keep thinking it’s poor polar alignment.
I may get to talk to someone from Skywatcher at a Star Party this new moon.

Regards,
Scott.