Hi again.

Sorry, another question. I have a 2019 49" Sony Android TV capable of both 4096x2160p(24,50,60Hz) and 3840x2160p(24,25,30,50,60Hz). However, when I try to switch my Duo4K SE's video output to 2160p mode, I just get a blank screen.
I've tried both the HDMI cable it shipped with and the 4K one I use with my UHD Bluray player, but no joy. I also tried turning off the HDMI EDID check.

Any idea why 2160p mode might not be working please?

Thanks