Azure Database for MySQL Flexible Server: Unable to Enable Private DNS Zone Integration — Post-Creation Limitations and Escalation Inquiry

Problem description

I am unable to enable Private DNS Zone integration for my Azure Database for MySQL flexible server. The server was created before the Private DNS zone support was introduced, so the option is not visible in the portal, and CLI commands to set it have no effect. I want to know if there's a supported way—via REST API, internal backend, or manual migration by Azure—to enable this feature on existing servers without recreating them.

Environment

Azure Database for MySQL flexible server in a virtual network with private access mode in a region not specified in the case information.

What I've already tried

I attempted to use the 'az mysql flexible-server update --private-dns-zone' CLI command, but it resulted in an unrecognized argument error or silently failed to set the privateDnsZone property. I also tried updating the network properties directly via REST API, which completed without errors but did not modify the privateDnsZoneResourceId. I confirmed that the server was created before the feature's release, which likely causes the limitation.

Current status

I am seeking confirmation on whether there is an officially supported method—such as backend intervention, API, or migration—to enable Private DNS Zone integration on existing servers with VNet integration. I would appreciate guidance on escalation procedures if needed.