Daily T3 Internet Time Out / Dynamic Range Window Violation Errors - Multiple Technicians Come out No Resolve

Hello,

I'm hoping someone from Cox will take note to this issue as dealing with another tech support technician on the phone who has us going around and around with turning things off and on is getting very old. We have been having daily T3 Timeout Errors and Dynamic Range Window Violation Errors for months where our internet goes out for a minute up to a few minutes and then resumes as normal and these are the errors the modem spits out. We were using our own Arris SB8200 Modem and just for kicks decided to switch to Motorola MB8611 Modem. Sure enough the same issues happens.

We have had 3 technicians come out. First technician checked the line and said the levels are good. Second technician took a look and noticed that the line from outside was connected incorrectly and there was interference happening with that line and the power line and it should be resolved within a week or so. Sure enough, that didn't happen and third technician claimed the coax that was running to the modem from the wall needed to be replaced and that didn't solve it either.

What can we do to get a technician that knows what they are doing to fix this issue?

Also, according to the internet my modem firmware is out of date, but Cox insists I had to do that with the manufacturer but then on the manufacturer's page it lists that the ISP needs to do it..