Data Domain Restoration Logic

I have an instance whose specific files (Certificate Authority, User Management, configuration and Keycloak entries) are to be backed up. We have a HMAC also present in the instance. The first time, I took a backup of all these files without HMAC. I tried to do restore testing and received the below error

"reason": "Exception as the integrityCheck.e2e.enabled=true in values.yaml and the e2eIntegrityCheck.checkOnRestore=true in brpolicy but the signed digest file is missing.", "status": "Failure"

I then changed the configuration to include HMAC also while taking a backup.
Without removing the 1st backup, I ran the 2nd backup with new configuration (HMAC added), The backup was successful.

I then tried the restoration of the 2nd backup and the restoration was also successfully completed.

When we verify the restored data at the instance, all CA entries are empty. Before backup it was present and after restoration its vanished. 

What could be the reason ?