The secondary controller sometimes says the sensors need calibration, the primary gives no such message, why the difference?

I have checked the primary after seeing the message on the secondary and there was no is warning visible on the primary.

I have noticed that the secondary controller generally connects first or rather it gives the connection display first.
Thanks

The secondary controller sometimes says the sensors need calibration, the primary gives no such message, why the difference?

I have checked the primary after seeing the message on the secondary and there was no is warning visible on the primary.

I have noticed that the secondary controller generally connects first or rather it gives the connection display first.
Thanks