Internet keeps losing connection

I have a netgear c6300.  It seems connectivity either slows down or lose connectivity between 11pm and 2am.  The last week, it keeps dropping dropping all together.  I was finally able to open my router specs and there were some correctables, but noticed that the upstream only locked one out of four channels.  I checked again in the morning and now it’s four out of four.  Is this a Cox issue or my router issue?