Hi, I'm fairly new to Unreal Engine and I'm having trouble with resolution with fullscreen

[JokerDDZ]

So I am trying to use fullscreen in my game. I created project from fps template (clean one, no changes from me) and I am trying to change resolution with the command r.setres 640x480f. Native resolution of my screen is 2560x1440. What I am getting after using the command is small window at the top right corner and the rest of the screen is black. I’ve seen this tutorial https://www.youtube.com/watch?v=8mmo35uA0j8 and when he tried the same thing he is getting correct fullscreen with this resolution (time: 7:26). What am I doing wrong? I am on version 5.5.1. Everything works fine with the command r.setres 640x480w. I am getting window with the correct size but you know, I want the same effect in fullscreen.

My specs:
GPU: RTX 2060
CPU: AMD Ryzen 5 3600

[JokerDDZ]

So I rerwrote everything in c++ and it still doesn’t work. It basically works the same way as blueprints. My code:

and the result:

I made all of the tests in standalone game mode