Consistent T3/T4 timeout errors

After doing research on this, it appears to be a recurring problem. Has anyone had a fix for consistent T3/T4 errors?

I have experienced this now through several modems (Including one rented from Cox), two different drop points in the house, and several different upgrades.

I had a very nice contractor come out yesterday and tell me that my brand new RG6 cables were ** because they were crimped not pressed, and that my brand new rocketfish high capacity splitter was ** because "it was gold". Evidently my signal was also "horrible inside the house but great outside".

He changed the cable ends, replaced the 2g splitter with a 1g and departed.

I get dropouts when I am attempting to do conference calls from work, as well as intermittent streaming issues when Netflixing for the kids.

Has anyone ever convinced Cox this is a problem on their end?