Can not create a migration endpoint in Office 365 to on-prem Exchange 2016. Everything else works, Outlook and OWA work. When I troubleshoot with Test-MigrationServerAvailability I keep getting "The RPC server is unavailable". I have tried autodiscover switch and manually setting the rpc server and exchange server. Same error. I have verified the user account permissions and valid login with OWA.
Any ideas would be greatly appreciated.