Some ideas, you might try isolating the NIC interface by disabling it and using WiFi instead to see if there is a difference.
One thought, you might try to install RoonServer which has no GUI and see if it installs. I would verify it is running, by connecting in with a phone, tablet or another computer running Roon. If it does and works, then it points to an issue with the Graphic System.
I personally run Roonserver as the server portion and Roon (only as a control interface) on the same machine.
Also, the latest NVIDIA drivers are NVIDIA 417.71. Your logs show you are using NVIDIA 388.57.