hi,

I ran a query into sys.database_files for both the databases and LSNs match but still I didnt restore. I think that is because the recovery plans are different in both the databases (which is unusual since I restored both with the same copy).

FYI, if the secondary is in Standby then we can restore a diff backup from primary but it will be read-only but not fully recovered.

Thanks for your time. I'm investigating and will update the thread.