Ping plotter results show bad cox hops. *question*

I've been having internet issues all day. Every day.
Ping plotter results show my ping spikes happening on hops 2, 3, 4, and 5. All cox hops. I've been reporting my ping plotter results to them daily. They claim that it's because of network congestion and they are working on it. The thing is that some of these ping plotter results were tested at 2am and even 4am. I know networks aren't congested at those times. Does network congestion leave lingering issues? Or are they just onto the wrong thing? Because i am skeptical