[Pepper (Steve)]

Help please people!
So up until the other night when i set my gear up and do an alignment I was able to leave the scope for a while without the star drifting off too much.
Last night I was out after a long cloudy period to get busy testing the new computer. Much to my dismay, the stars seem to drift waaaay to fast?
With sidereal tracking chugging away the star will drift (movement every second) from centre towards the rhs of finder. I need to up and right button to recenter.
Turn tracking off and they rapidly start heading toward bottom left of finder.
Now this was never anywhere near as pronounced on any previous night.
Can’t even get a 2 second shot now??
Any ideas? This is driving me mad.