Failing back to the original Primary using difference-based synchronization involves the following steps:
To fail back using difference-based synchronization
Converting the original Primary to a Secondary of the new Primary.
Synchronizing the data volumes on the original Primary with the data volumes on the new Primary using difference-based synchronization using Storage Checkpoint.
Starting replication to the Secondary (original Primary) using Storage Checkpoint.
Migrating the Primary Role to the original Primary and starting replication by default.