Fullscreen is always full native Resolution

Hi there,

When i switch over to fullscreen with console commands from a blueprint, the resolution is always full HD. So the maximum from my monitor. If i set a command like “r.Fullscreemode 1” and then “r.setres 800x600(f)”, then the screen gets to fullscreen with 1920x1080. There are no Pixels and artefacts visible as would be from a low resolution setting like 800x600.
So am i right when i say, the only way of setting fullscreen proprieties is the way via the screen percentage settings, which are described in the scalabillity reference? Is there no other way to blow a 1280x720 Resolution up to fullscreen? Maybe it depends on bug/problem i have at the moment. I can only switch to Fullscreenmode 1 successfully.
Fullscreenmode 0 doesn’t work for me now.
Any clarification about that would be nice. Thanks