Omniverse Create - Cloud XR - Error 19

I want to use Cloud XR to connect my phone to Omniverse create, to view a model in AR.

I run the CloudXR app, and enter that IP. It shows “Searching for surfaces”, and finds some surfaces. When I touch on the screen it pauses, and then quits showing “CloudXR ARCore Client: Error [19], see logs for detail. Exiting.”

If I run Wireshark at the same time, I see the following rejected connections:

I have disabled firewalls.

I realised that perhaps I need SteamVR. I ran that on the server machine, but it did not make any difference.