There is a setting on the xbox to fix 4k for some TVs, does that not fix that? Or does that happen on the smart TV menus and apps as well?
First XBOX needs to recognize that there is indeed a 4k TV connected to it. I was playing with Standard and Enhanced mode in system settings. But to be honest I was trying so many things I cannot tell you for certain what fixed it nor do I know what caused the flickering after that.
Have spoken to Allincluded and they will swap out unit for me.