Unreal 4.4.3 SetRes doesn't work

I am in the process of making a game and I want to make sure that users can set the resolution of the game in case their computer can’t handle the resolution of the monitor that they are playing on, but I can’t get the resolution to update and stay updated.

For instance, if I launch the game as a standalone and run the code

GSystemResolution.RequestResolutionChange(800, 600, EWindowMode::Fullscreen);

The game will launch in standalone windowed mode with the resolution equivalent to 800x600, but the actual size of the window will only take up ~25% of my 1080p monitor. The second I click the fullscreen button in the corner, the game is made fullscreen and the resolution jumps to 1080p. How can I prevent that? Is this an issue with 4.4.x?

I have also tried just running the console command

r.setRes 800x600f


setRes 800x600f

And neither command works properly. The game is always played at 1080p when in fullscreen mode.

How can I fix this? Am I doing something wrong?