Parameter function changes Cube Black (Foxtech) to 4.0.6

I have a Nimbus VTOL from foxtech. When I received it I had to update Ardupilot and parameters. Foxtech advised to use Cube Black Apj (version they sent me) and their PG20 cube black parameter list, which I did. All seemed fine until I tried to use Cube Black apj for QGC and got an error related to compass.

It was then suggested that I should update to 4.0.6. because the supplied which I did and re-installed my parameters. This process reversed 1 of my parameters relating to the PG20 and it was drawing from the wrong battery in vtol mode, leading to minor crash due to drawing excessive AMPs in Q mode for low 3c battery. In addition to this it also disabled Q YAW function- which I did not identify in preflight checks as in fixed wing all surface controls performed correctly.(lesson learnt) I was able to fix PG20 issue by reversing servo7 as suggested by foxtech to fixed PG 20 battery preferences, however nothing appeared to fix Q YAW function
I have now reinstalled (Foxtech) Cube Black and last correct functioning parameters and all systems appear to work as normal-PG 20 and Q YAW . I feel something has changed in the back end between these versions.

As I’m new to Ardupilot is it possible / common / rare for new Ardu pilot builds to change /remove existing parameters.