Whats are the tolerances for suspension calibration?

I've replaced all 4 sensors, re-calibrated (many times) and the front right height is always 20mm lower than the front right.

It doesn't sag overnight, so I think the struts are ok.
It's a new pump and works fine.

Is it just old - accept it - or in tolerance - accept it? L320 Range Rover Sport 2008
3.6 TDV8