Unable to select secrets from replicated Vault while creating a custom end point for Visual Builder

We are creating a common custom end point for 2 Visual Builder instances stood up one in Phoenix (Primary) and one in Ashburn (Failover). One of the configuration step is to provide a certificate for the common domain name. So we created a Vault in Phoenix region and uploaded the certificate as a secret in the Vault. The Vault is also configured to replicate to Ashburn region. I verified that the vault exists both in Phoenix and Ashburn. I was able to configure the custom end point for the VB instance in Phoenix and test it successfully.