r.setRes wf doesn't set windowless fullscreen [Mac OSX]

I am having problems in getting into fullscreen mode. hitting F11 makes no difference.
I am using Unreal Engine 4.24.3 in a Mac OS Catalina (10.15.4). I saw in shortcuts that it should be Cmmd+ctrl+F, but even that is not working for me to get into fullscreen mode. Any clues?