RDP to external 3rd party server timing out

We have one user that uses RDP to connect to a system externally. They have been at home when they started using the connection but it does not work anywhere on the corp domain. It just times out.

I discovered that if PC or server did not have the domain network profile applied (It was stuck at discovery) it connects and works fine.

Have been through group policy and rdp ports are open. If you run a netstat you can see an established connection.

Clients are windows 10.

There must be something I am missing group policy/firewall

Thanks