Hi @Chairing,
Welcome to the Roku Community!
We understand you're having a problem with your Xbox since it will show no signal on your TV. We're happy to help. We suggest checking the cable connections and the HDMI cable first. Also, verify that the correct input source is selected on your TV. If this does not work, unplug and re-plug the TV and console for 1-2 minutes, disable VRR on the TV, and boot your Xbox in low-resolution mode.
If the problem still persists, please keep us posted.
All the best,
John
John
Roku Community Moderator