When I edit config.txt, trying to force a certain resolution, RasPi always comes up with the monitors preferred resolution. After a lot of trying, including a completely new fresh OS install, I have come to the suspicion that when the desktop initialises, it also re-re-initializes HDMI So the read of config.txt done by the GPU at boot is undone.
However, when I edit the resolution with the Preferences->ScreenConfiguration, that one holds, but it does not modify the /boot/config.txt. So that utility is someone called during desktop start and is my undoing.
I am pretty sure about this: When I manually edit config.txt, depending on the modes that I select, I quickly see the boot logo pass at various sizes, depending on the mode I did set. But it always flashes again when the final desktop loads and jumps to the resolution set with the utility.
Can anyone confirm? How to disable the utility? From SSH preferably. Or better yet, how to also add custom resolutons into that?
BTW: the mode I am trying to set is a DMT mode. (I tried with and without the :0 of course)