I have a Windows 10 1803 Enterprise host with a Windows 10 1803 Enterprise guest running on Hyper-V. It might be worth mentioning the guest was migrated from VMware.
All of the Hyper-V Windows features are turned on on the host.
The host has a GTX 1080 for a physical GPU and it is enabled for RemoteFX.
All of the Integration Services are enabled.
With no RemoteFX 3D Video Adapter installed in the virtual machine, it uses Enhanced Session Mode and it's great. I am able to copy/paste between the guest and host, I am able to play sound.
When I add a RemoteFX 3D Video Adapter to the virtual machine, I am no-longer able to copy/paste between the guest and host. There's also "No Audio Output device" installed. Removing the virtual video adapter fixes the issues immediately.
I'm unable to find documentation that you can't copy/paste or play audio with a video adapter installed.
Why are clipboard and sound unavailable when using the RemoteFX GPU?