1) I found the setting in the BIOS that was turning the thin client on every evening. I just needed to look harder.
2) The best video setting for dolphin for me @ 4k resolution is:
* leave vsync, texture filtering and antialiasing off
* set the render resolution to “ Auto (Multiple of 640x528)”
* use vulkan.
We had been wading though some muddy looking, poor performing sections of Twilight princess with other more complicated settings. I had been too tweak happy. Went back to the basic settings @ 4k and the performance improved and the games look better than I thought possible. Textures, lines, & hud are very crisp and vivid.
Next step is to see if I can stop the sound stuttering at the odd times when the frame rate is below 30.