Fortnite Streched does not work for me?

I have really tried everything as it is described in the gamerusersettings on 1440 x 1080 then in Nividasettings do the same (on native) and still the streched attitude is not. It turns back to 1920 x 1080 every time you start. Can someone please help me I'm almost despairing

1. In% Set LocalAppData% (where everything is resolution)
2. Make sure that the file is read-only again
3. Create a resolution in Nvidia / AMD / Intel (on laptops) and enter the values.
4. Switch to the resolution.
5. At Desktop Position and Size… (Nvidia)
Activate full screen and also set the resolution there

* own