Not sure where you are located, but in Mesa AZ where I live, we experience the same for nearly the entire month of November. We had cables changed. The node at street did have a messed up splitter on it, sending half of my signal to the house and the other to an underground conduit the tech could not identify. There was also and old piece of equipment in my connection box at house that restricts my request signals. That was removed.
In any event, we still had issues until a board was replaced at street node. According to a Cox rep in Fla, there are ongoing upgrade issues. We dropped signals repeatedly for several weeks. Sometimes it connected in minutes, but as long as 8 hours. No reset of modem or router was going to correct that issue. I chatted and spoke to several reps during those events.
As of today, it's better. The board seems to have stabilized system. However, my usage has gone up 50% with no change in our behavior. I don't know why, and would like that explained. Somehow our usage was the highest ever last month with the problems. It's just 2 of us in a rather remote area so no hostile users on my network.
I'm on pace to equal last months high...unexplainably. I intentionally didn't turn on TV's the past couple of days and it still registers double what my typical usage was in September. It crept up in October and jumped in November.
As for your problem, it's hardware upgrades that need to be installed from what I can tell...and what one honest rep in Fla said. He also said...you can't get a discount without begging and they can only give a week at a time.
Best of luck.