I have a Pi model 3B. I used Raspberry Pi Imager to install the latest Bullseye onto the SD card; the installation was successful. The Pi is attached to a monitor with HDMI cable.
I have VNC and SSH enabled and they working well also; both the "live screen" and the screen I see over VNC are in the correct resolution.
As soon as I booted the Pi headless, the resolution I see over VNC is dropped to 720x480. All methods of changing the resolution (In the RPi Configuration, editing the config.txt...) do not work. I do see in "Screen Configuration" that HDMI is not enabled and the Pi is outputting Composite-1
Even if I now plug in the HDMI cable and attach a monitor, I do not get an image on the monitor. Over VNC, I can see the Pi is stuck in Composite-1 mode.
Any thoughts? What I want is that I can run the Pi headless and have a 1920x1080 resolution over VNC.