The CEM 40 is a normal mount and other than having it connected via an USB hub there is nothing different about it. It is a popular mount a good quality one with good performance.
In your case you will need to adjust the guiding settings according to your guidescope focal length and develop good calibration habits.
- disable "Auto Restore Calibration"
- make sure you have a good Polar Alignment
- tune your mount to get rid of any backlash
- calibrate always around Celestial Equator (not on targets close to NCP)
- make sure the mount is well balanced on both axes
- adjust exposure in such a way that you don't guide on saturated stars (in the small preview on the right the value is well under 255)
- adjust guiding aggresivity properly to fine tune guiding
As about why calibration takes a lot of time - you will need to increase Calibration Step.
Recommended reading for you: https://eastwindastro.blogspot.com/2021/02/how-to-adjust-asiair-guide-aggression.html?m=0
And everything else on that blog
