App Service Certificate Create Key Vault Fails

When you create a new App Service Certificate you need to associate a Key Vault to the Certificate.  

When doing this if you have no existing Key Vault you can click an "Add" button to create a new one within the certificate.  This functionality no longer works and the deployment fails with an error and Microsoft Support suggested I add this here.

The workaround is to create the Key Vault normally, then go back to the Certificate.

If this feature isn't going to be fixed, I believe the "Add" button should be removed.