My screen flickers white for a split second

Also when i first connect the headset to my xbox and start a party to test it, the circle around my picture flickers up for a split second and my name on the overlay does the same, then nothing after that.

I've never used the Roxio, but I have used the Dazzle before and the top portion of the screen was always flickering and had white lines. The only solution I had was to crop it out using an editing program. Have you tried cropping a bit of the bottom screen
to remove the flicker? Either that or it sounds like a wire maybe loose.

Hey! The same thing happens with me! Probally a bug in the game, i play on a Xbox One S and wherever Picadilly loads in, some poligons start to randomly have a seizure across the screen, also if the second player uses the Dead Silence perk, the "glow" of
the second screen takes over the first screen, creating a white filter.

Looks like no one tested split-screen on Xbox before launch...

Not many games will have split screen for online play as it affects frame rate. You could check Split/Second that definitely has split screen, I'm not sure if it allows you to play split screen online tho.

I don't think there is a split screen option on this game. Blur and split/second are both racing games with split screen that you might want to check out.