Help with Sophos HA

I need help with that's cenario:

HA Active-Passive Configuration ( Preferred primary device flag DISABLED ) :

XG106_A > Initial primary ( initially with license )
XG106_B > Initial auxiliary

At a certain point XG106_A stopped responding and XG106_B became standalone.

After analyzing the XG106_A in an 'isolated' environment, it was necessary to reinstall its latest firmware as it was corrupt.
To reinstall the firmware on the XG106_B device, it was necessary to deactivate HA.

How do I proceed correctly to activate the HA again, will it also be necessary to deactivate it on the XG106_B device? If this is the procedure, initially the license was on the XG106_A, how should I return both devices as primary/secondary?

XG106_B is functional and I cannot lose client environment settings

Thanks