Rpi3 and 4k

In this case, your grabber will ensure that only FullHD is played back, which is connected to the splitter and then states that I can only do FullHD.

This will be a problem of the EDID data.

It is best to use a splitter that supports EDID Copy from the TV, then you have the best resolution that the TV also supports and Downscaler to Grabber.

RPI3 has HDMI 1.4, 3840 × 2160p @ 24 Hz

regards pclin

The grabber will be one with a macrosilicon chip. Input resolution is probably FullHD. The splitter can probably only do 4K 30 Hz and no HDCP, Settings for EDID are not available, probably no downscaler for the grabber either.

It's best to read here.

regards pclin