I worked for TWC cable for 25 years and I can tell you that they do very little any longer to invest in the training of their people.
I had a tech come to my house and did not know I was a retired employee, he spent the first 20 minutes trying to pass the call to another department, never took out a tool, meter or anything!
Long story short, it was a bad two way splitter on the back of the house.
Cable broadcasts down a sealed system and 80 to 90% of all cable issues can be traced to bad F connectors, If you get a tech to your house and he does not change all of the connectors, at least outside, you have been screwed. The low band is never an issue but as you get to the hyper band signal loss is dramatic!
INGRESS!!!! OR EGRESS The next biggest issue they never fix, that is why they don't run the local channels on the same freq they are broadcast in, and don't tell me you can not seal it out because before we where bought up, I worked a system the ran the local. 4 , 5 and 9 on those channels and we kept the system tight,, The Gov came up with something called CLI and the cable industry spent more money getting around it than fixing the issues, Anybody that has leaks will get beats on a lot of channels from pagers and phones but it really will wipe out channels 19 and 20. I forgot the freqs of these channels
IF that is not done water gets in and you never find it until it has done major damage.
If you installed ANYTHING from radio shack in your house, your asking for trouble, get rid of it!
Bottom line, if you can get a tech to your house and all he/she wants to do is swap a box until he/she finds on that is more tolerant or just happens to lock up for a while, MAKE them service your entire system all the way to the pole or pedestal in your yard.
Do not ever use the cheap ass jumpers that come with VCR'S or any vid units you buy, You need a good piece of coax with at least 80% shield and foil.
IF you had some old RG 59 and they installed RG 6 in you house, you will find you can have connection issues in your equipment if you install something with a center conductor smaller that RG 6. It spreads the tabs in the connector and if you go back to a smaller center conductor, sometimes it will not make good contact and on digital, its critical.