You don’t need the camera mounted at all to do the lens calibration, and in fact, we now have calibration presets for all the cameras we sell, so you only have to do the alignment, not calibration. When you calibrate, can you post an image of the calibration page just before you click the ‘Capture’ button? I’m guessing if I see that I can tell you why you’re having trouble.
The most common user issues are documented here: The camera doesn't find the lens calibration pattern (pattern NOT found)