Screen resolution - no way to change it

Hi everyone!

I bought a BPi M4 a week ago and I’m continously struggling with the display. There is NO WAY to change the screen resolution, it’s stuck at 1920x1080. I’ve downloaded all the available kinds of linux distros for M4 and nothing works. Config.txt - no effect. uEnv.txt - no effect. Raspbian’s tvservice returns “failed to initialize VCHI”. There is only “U:1920x1080p-60” listed in /sys/class/graphics/fb0/modes. Nothing else. It’s hopeless, I think I’ll return this useless piece of hardware. Unless someone has any ideas. Thank you!

No one? Where’s the official support??? It’s supposed to be a “SinoVoip BPI team”, isn’t it?

M4 HDMI resolution is decide and set according to your monitor edid.