Once try to delete array pair you are giving error:
"Operation Failed Unable to remove array pair 'ArrayPairName' - 'ArrayPairName'. Array pair is in use by one or more protection groups"
In order to successfully remove an array pair, it cannot be in use by any of the protection groups.
Perform the following actions before array removal attempt:
Contact the array vendor to progress upgrading the array pair on array side if its required.