Application Gateway v2 "trusted root certificate" configuration via portal
To configure end-to-end encryption with Application Gateway v2, cer is not supported for Backend Authentication Certificates under the HTTP settings. Using this will result in an error stating authentication certificates are not supported for v2. A Trusted Root Certificate should be configured for v2. This option seems to only be availalbe via powershell and not through the Azure Portal.
Please update the portal configuration options under "Add HTTP Setting" to allow adding Trusted Root for v2 gateways and not just Authentication Cert.