Low Upload Speeds, Cox Techs aren't able to fix

So as the title says I'm experiencing intermittent low upload speeds, usually in the ballpark of 1-3Mbps with packet loss. I have had 4 visits from technicians, 2 contractors and 2 from the "escalation team" without much success. The escalation team replaced all the wiring to the house and certified the wiring in the house stating that it would no longer be a problem. I'll be recontacting them soon. I still get poor upload speeds, again intermittently. Is there anyway to self diagnose if the problem is on my end or cox's? If so, what do I need to do? Thanks.