Xbox one x going bad

You don't necessarily need a 4k television to run the Xbox One X. It will still scale to any television display. 4k is just the maximum optimal display. You're good to go.

Please, can you provide us with more information= Describe the problem in specific.

How to change the display resolution for your TV on Xbox One

Your Xbox One console automatically detects the display resolution on your TV. However, on rare occasions, your console may not detect the TV's resolution correctly. If this happens, don't worry. It’s easy to change the display resolution:

1. Press the Xbox button to open the guide.
2. Select System.
3. Select Settings.
4. Under Display & sound, select Video output.
5. Select TV resolution, and then select either 720p, 1080p or 4K UHD, whichever is best for your TV. Note If you don't see the resolution for your TV, make sure to set TV connection to Auto detect.

If you're experiencing a blank or black screen on your Xbox One display, see Troubleshooting a blank TV screen or monitor while
your Xbox One is on for help troubleshooting the issue.

Hey there Lubos69,

Are you having an issue with the display on your Xbox One X? If so, have you tested on different monitors or different HDMI cords to see if maybe any of that will resolve the problem.

If this is not the issue then please provide us with a bit more information so that we provide further assistance.

Thank you.

I turn off option "Allow variable refresh rate" and it is probably going OK, no bugs. But it should go when it is turn on because I have monitor with Freesync.