KSP 1.9.1 x64 - Unable to change resolution

[Corovaneer]

Game automatically sets resolution to desktop resolution, ignoring the settings.

If I try to set resolution to a lower value to increase FPS, it changes while I am in the menu, then reverts back to HD as soon as I load the game or if scene changes.

settings.cfg has resolution set to desired lower value on startup, file is not overwritten, but is ignored. If I check the options after startup (while observing HD res), settings.cfg has lower value.

AnyRes mod will change value in-game to a lower one, but the setting is not kept (resolution reverts to HD at every scene change).

The behavior reproduces roughly 80% of the time (sometimes settings are kept, but I can't reproduce why)

The only way to reliably have resolution setting that you want is to change desktop resolution in Windows.