Can't make my packaged game open in 4:3 or 1280x960 resolution.

I’m making a simple retro game and I’ve worked on it on 1280x960 in the engine. But when I package it it always opens fullscreen stretched (I have a wide monitor 2560x1080). Now I have tried putting a set resolution in blueprints on my Event BeginPlay in my MapMainMenu Level Blueprint as I saw in one of the Unreal forums, repackaged and nothing. I also tried creating DefaultGameUserSettings.ini in the Config folder of my project files and setting the resolution from there - still nothing. I’ve tried both at the same time, clean recooking, repackaging, deleting Intermediate, Saved, Build folders and redoing everything but to no success. I’ve run out of ideas so I’d love some help. That’s all that’s left for my game so I’m excited to have it finished! Thanks in advance!
I use Unreal Engine 5.6.1

I think you need ‘windowed’ rather than ‘windowed fullscreen’? ( from what I can recall right now )

I just changed it in Blueprints and its all good! Thank you so much and for the swift response!