its not the cable. in any case mine is a 48gbps as well. Im in Australia where TV and content are 50hz Pal as opposed to 60hz NTSC which is what you are using. I have set it manually to 60hz so the UI is faster.
With match content on, it should correctly adjust content to the correct frame rate regardless of what the UI is set too.
What I have found is
with 50hz UI, the screen goes black when scrolling through music videos and also when it maximises to fill the screen.
This is actually correct behaviour since most content in music videos would be 30fps and the TV needs to switch to that from the default 50hz. This causes the black screen. Unless HDMI 2.1 is enabled, fast switching won't work. I believe its called QMS which you can google about.
What shouldn't happen though is if the UI is set to 60hz and match content on, the black screen between switching of music videos should not happen since its only doubling of the 30fps but it still does...
Now what bothers me even more is not the black screen but rather the pausing of music
With my Apple TV 4K Gen 1 connected to a stereo set of homepods, the black screen still occurred but the music wouldn't stop playing and I was fine with that.
With my Apple TV 4K Gen 2 and the exact same setup. The black screen appears, the music plays still... then the image appears, music stops, the scrubber goes back 1-3seconds and then music resumes.
so if I set it manually to 50hz SDR and have match content off, the black screen doesn't happen, the music doesn't skip BUT the video has judder
if I set it manually to 60hz SDR, turn match content off, every works perfectly well for 30/60fps content unless I use an app like amazon UK or any Australian app where the frame rate is 24fps and then it everything is just sped up and artificial.