Display MoreI think this is an issue with your TV (firmware?).
Intel driver default to 4K/24 12-bit RGB. Maybe your TV doesn't like this video mode.
Try to force 8 and 10 bit with proptest (copy it to /storage and chmod 755)
# systemctl stop kodi
# ./proptest
It should look something like this (values may be different for your box):
# ./proptest 326 connector 328 8 (this will force 8-bit for Connector 326 (HDMI-A-2))
# ./proptest 326 connector 328 10 (this will force 10-bit for Connector 326 (HDMI-A-2))
Then
# systemctl start kodi
and try to switch to 4k/24.
I have the same issue on my NUC11TN no 4k/24 unless 8bit is forced. The gemini nuc was fine.