Promote AWS Postgres RDS Read replica - Error : Physical replication

Error : InvalidParameterCombination: Cannot change master user password on an RDS postgres Read Replica because it uses physical replication and therefore cannot differ from its parent.

This error comes whenever i am trying to promote an existing read replica to be primary. As per the theory, removing the rds instance arn should do the job but in my case, where the primary rds is encrypted, the promotion of replica leads to an error.
But re-executing the same module promotes the rds.

Any thoughts or suggestions.

I have replicated the secret in the new region and passing the username and password to the module.