[PC] Incorrect resolution output in fullscreen mode

When running the game in fullscreen the game always seems to render at the requested resolution but output at the monitor resolution (in this case 1920x1200), leading to a blurry fullscreen mess instead of obeying GPU scaling settings (Radeon HD 7950, W10H x64). It also seems to refuse to run at anything other than 1920x1200 in borderless mode (not my preferred setting anyway).

I have replaced any references to the 1920x1200 resolution that I have found in PoplarGame.ini and PoplarEngine.ini but to no avail.

Is there a hidden setting or switch that is not working correctly?

Same problem, even in small resolution