Spotty and unreliable Home internet service

I live in NW Las Vegas and I find my wifi is very unstable especially at night. There is only about 15 devices connected and most of them are not in use.  Sometimes I would be up late at night (after midnight) and internet seems to be always cutting out after few mins of simple web browsing. I even had a technician come check the wires coming into the house ( he didn’t find any wire problem) and even replaced the modem. This problem still exists unfortunately .  Lost connection almost daily! It is extremely frustrating to say the least. Is anyone else having similar reliability issues with cox in Vegas? I have both the internet and security service with cox and I am on 500mb mid tier service. I am seriously thinking of changing the provider if this problem persists. any advice on what to do? Cox service rep both