No signal when putting interface in 4k

I have a Philips TV (49pus6262 / 12) and CE 9.01 (DMYCO TV box with S905X and 2 GB RAM) and when I set the resolution 3840 × 2160 the TV I get the warning of no signal and black screen.
But when I play a video in 4k with HDR from my external hd it plays it well and the TV shows the activated HDR warning.
Does this mean that if it works at 4k though on the interface, is not it?
I searched the forum and I read something with the help of the google translator but version 8.9x.
Thank you.

You need to check the HDMI cable.

I have used three cables and the three ports of the tv and in all it happens the same.
What cable do you suggest?

You can try this solution in additional to cable

I use a Philip’s 50PUS6703 and that mode is not necessary, it’s most likely your cable.