My first
MA requested compass calibration nearly every flight. I have a smartwatch and used to remove it before flight. Didn't reduce the problem much, if at all.
Didn't seem to matter how far I had travelled between flights. Even returning to change battery and taking off again from the same spot would usually require a calibration.
Had a fly-away event last August ( there is a thread on that) and DJI replaced the
MA as their investigation concluded no pilot error / equipment malfunction.
Never been asked once for a compass calibration with the replacement drone.
I have to conclude there is a problem with the unit if it keeps demanding calibrations.