4K video output resolution issue

I have the xi6 wireless 4K box connected to a 4K Samsung tv.
The only video output resolution that works is 1080p60 even though 4K resolution is marked as “best available”. If I choose 4K setting the screen goes black and my tv no longer recognizes the cable box and goes to a “no input” screen.
I have to type exit-exit-1080 for the box to change back to a resolution that works.
Even a lower resolution causes issues (glitchy picture/sound).
What is the solution for this? Obviously I’d like to have resolution setting to best available.