Hey @Rollmop,
This check is more a debuging message. If you’re sure what your people pair number is you can discard the error messages.
The issue might be in your motor’s cogging or something similar.
In my experience, 500ppr is not too low of a resolution and results is a good estimation of the pp number.
Did you try the library example code in the utils > find_pole_pairs_number
Can you run your motor in velocity mode for longer periods of time whole continuously turning?
Which library version are you using?