Hi, thank you. I happened to be in the middle of a major revision and wasn't able to work on anything else until completed.
There is no quality or resolution dialog, so my client isn't changing settings on start. I checked Quality in project settings, and the highest (Fantastic) is default.
I haven't upgraded in a while; I'm still on 3.5.9. I think I remember Constrained UI being an option, but I don't recall where. Under UI Root, for Scaling Style I only see Pixel Perfect, Fixed Size, and Fixed Size On Mobile. I have it set to Pixel Perfect. My client's monitor just happens to be a lot larger; I'm on a small laptop. I don't allow a resizable window, so my client can't be changing that either.
I'm not forcing OpenGL, so I assume it's defaulting to DirectX. Are there any other possibilities?