same here, when I moved to my new house cox internet and TV was up and down constantly. at night it would be fine, but during the day it would drop packets and my modem would constantly reconnect. I called cox about it about 10 times, I had people come out and test, and everyone told me it was fine or my equipment. was bad even though my equipment worked fine at my old house. so I broke down and bought a new modem. everything was still the same. I had the technicians replace cables and ends and run every test they could, but when they were here there was no problem. within an hour of them leaving the problems would return.
I worked in IT for 22 years. I don't call COX unless the problem is out of my control. Navigating COX's phone system is a nightmare. getting someone on the phone that actually will listen, and not force you to go through all the troubleshooting steps you have already tried is near impossible. I have endured hours on hold, then suddendly being hung up on when I have not even talked to anyone. People who straight up refuse to send me to Tier II support when I ask for it. Automated systems designed to make it difficult to get a person on the phone. Automated systems that say my equipment was working fine when it was not even connected. I worked on a help desk as a tier II technician for the State of Arizona, and would have been ashamed to treat people the way I was treated.
I downloaded software that monitored my internet connection and could provide graphs of when the problems were occuring, and no one at cox was interested. I could even tell where the problem was occuring between nodes. no one cared.
I spent hours on the phone, and eventually gave up since cox would not take ownership of the issue. then one day a few weeks later cox announced that they would be upgrading the equipment in my neighborhood, low and behold it improved 10 fold! it still has problems but nothing like it was.
my recommendation is call the sales department.
or maybe some of these people might help https://newsroom.cox.com/contacts