Internet disruption all devices wifi and hardwired at the same time.

Internet disruption all devices wifi and hardwired at the same time including DVR TV boxes. This issue has occurred for a year and a half since upgrading to gigablast with panoramic wifi. Cox tech guys have replaced all wires and splitters. I exchanged modem about 2 months ago. Cox truck checked wires throughout entire neighborhood last 2 days. All with no results in fixing issues. All the tech guys I have interacted with have been professional and feel like they tried to fix problem. I have no idea what the problem is, and almost feel like its unfixable at this point. Hate feeling like the guy who just complains, but the constant disruptions with anything we do using internet is beyond annoying. Looking for advice or do I just move on to different service.