Xbox restarting when I switch to PC on shared monitor

what audio do you have plugged into the xbox?

Anytime that the xbox is plugged into a display via HDMI it must remain on the screen and not changed between videos. I'm not sure why, but I had the same issue and I noticed it's only with the HDMI, if i changed to a different video input on the screen then back to the xbox input it would make it restart. With component cables connected it isn't the same result.