Time Warner Cable Is Not Neutral Toward CDN Traffic
medium.com
medium.com
Some excerpts: https://twitter.com/stopthecap
You really need to do a comparison. Maybe after dinner and after midnight run a comparison between your cable connection and your wireless phone connection. Pick a movie and test both. As WFM mentioned, if you can run a traceroute, you can see how your home connection gets to the CDN. In some cases it might terminate at Time Warner, but probably most cases it terminates at the CDN or the content owners origin(Apple for example).
I kinda expect that the after dinner test will suck and the after midnight ones will be much better. You would still need to narrow it down from the cable connection vs the origin (content) server. One way to do that is to compare a video on netflix vs instagram vs youtube. You are looking for throughput and errors/buffers.
You could also check this: https://www.google.com/get/videoqualityreport/ https://www.battleforthenet.com/internethealthtest/
I would say complain to the FCC, but...