Then last July ('16) I switched to Directv where they have some 4K content and for the most part, got either no DTV 4K or very little.
When my DirecTV receiver was replaced last year I started getting DHCP errors on my 1080p television. My signal path is somewhat long: DirecTV > Oppo BDP-105D > Yamaha AV3000 > Panasonic Plasma which certainly didn't help things. What was confusing was that my Apple TV and Oppo worked just fine routing through the Yamaha. The only thing that had changed was the DirecTV receiver and that was the path that was failing.
I found an article that listed cables at the time that would support 4K when I'm ready to upgrade. Monoprice, Monster, Wireworld, and Audioquest all had cables which failed to deliver at least one 4K signal type. I finally just replaced the cable from my receiver to the TV with an Audioquest Carbon that I found for 1/2 price and haven't had a problem since.
https://www.soundandvision.com/content/uhd-blu-ray-vs-hdmi-let-battle-begin-page-2
The HDMI 2.0 spec supports up to 18 Gbps. As discussed in the article, the splash screen on the Samsung UHD player tested was outputting an 18 Gbps signal which is at the top end of the 2.0 spec. So even a good cable can fail it the signal is pushing the edge of the HDMI spec.
The bottom line is that the functionality of an HDMI cable is dependent upon the cable's construction, length (over 5 meters is problematic), certification (HDMI 2.0 or 2.1 which will go to 48 Gbps), and electronics in the signal chain. If you have a simple installation (just, say, a connection between an Apple TV and your television) then an inexpensive cable will likely work. But as you add more components, increase the total signal path length, push more data such as 4K 60 Hz, you may start running into problems.