Well 30Hz 4K is 4K, but only needs the bandwidth of HDMI 1.4. So saying 4K for a cable doesn't mean much.I had an issue with many dropouts as well, but on all firmware. I discovered it was my HDMI cable. It claimed to be 4k capable but I think while streaming 4k content it didn't have the bandwidth and the audio skipped.
I swapped it out with another cable and all skipping went away. I need to find a ~20' HDMI that has full bandwidth as I'm now just using a shorter temporary one.
Being certified premium high speed HDMI on the other hand means something (if you need HDMI 2.0 speeds). Or better yet certified ultra high speed HDMI (if you need 2.1 speeds). Certainly for 2.0 speeds, getting a certififed cable is easy (monoprice has 20' for $24 for example).