Robsteriark
Not enough information.
Have you tried unplugging and refitting the HDMI cable at both ends? (Cats/dogs sometimes knock them slightly loose if they go behind the TV and console units).
Does it only happen on that single HDMI input socket or does the problem continue if you use other sockets?
Does the problem continue if you use a different HDMI cable? (On a failing cable, problems like that sometimes get resolved by swapping the HDMI cable ends over).
Does it only happen with that XBox, or also with other devices like other consoles, DVD/BluRay players, satellite/cable boxes, Roku/FireStick/Apple TV?
Have you tried a power reset on the console?
Have you tried the same thing by briefly unplugging the TV from the wall outlet?
Are both the TV and the console running up to date firmware?