Video signal

ive had a similar issue to this, the HDMI cable I was using worked with a blue ray player but did not work when connecting my console, try using a different HDMI cable. might be a quick fix, also the connection to the console can sometimes be a bit finicky,
try playing around with it watching for any flicker of a connection, had to play around with mine more than once

Try replacing your hdmi cable

Hi Shurst021373,

Thanks for coming to the forums for help. Sorry to hear that you are having issues with your Xbox One X losing video signal. Have you tried changing your video settings on your Xbox they could be still set to 4K output when you change over to 1080p. The
following steps may help you solve your issue:

1. Press the Xbox button
    to open the guide.
2. Select System > Settings.
3. Under General, select TV & display options.
4. Select 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 the
   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 in troubleshooting
this issue.

Im sorry hear that lazy Yankee fan but lets try using the process of elimination

1.Make sure the hdmi works with a dvd player or your cable box

2.if it does work then try connecting to the tv directly without the cable box and if possible try another tv.

3.If your still experiencing issues make sure your using the correct hdmi slot the one that is suppose to be plugged in should be HDMI OUT right next to the power cable in the back.

Tried and debunked everything. Hdmi port is faulty just like everyone elses with this same problem im sure. They were made with crappy hdmi ports or assembled poorly. This is too frequent of an issue for Microsoft to solve this. Consumers pay way too much
money for these console just to have a hdmi port go bad in a year. Ridiculous!!!