This happens sometimes also when TWC sends out firmware updates overnight. Having a composite video output running along with HDMI should not cause any issues to arise. I had that done for over a year with no issues.
I’ve seen more times than I can count it work fine for someone when they go to bed and the next morning it’s shit. Go with first reply. Unplug box from all wires/power. Hook up HDMI once the box is powered on AND configured (i.e. once it shows the time).