Because the Care refresh is bound to the RC 2 at present
This is so when you have a fly away you can only claim with a bound controller so you are not scamming DJI
So when you connect the Motion 2 it will warn you this is not bound to the care refresh so if it flys away you are goosed
If you do bound it then the RC 2 will not longer be bound to the care refresh and will then give the same error
Basically you have to move the care refresh binding to each controller every time you change them
Actually thinking about it, it may be the goggles that carry the binding
Let me check BRB