forced to my xbox

Why does my halo 4 playing sometimes switch itself to “my Xbox” while I am playing. I switch it to “Xbox live” and it switches itself back to my Xbox.

This has happened to me once or twice. Seems to be an xbox live issue because it’s never just me. If I go to xboxlive.com and message the friends I just got disconnected from, either they got disconnected too, or xboxlive.com is down as well.