I also have match frame rate off, although I kept match range on. All of my other settings are default with 4K SDR 60fps. Channels has worked perfectly with this config and I experience only occasional frame rate jitters with other apps. Luckily I don't watch too many series in 25fps and everything generally looks good.
I'd love to have the confidence to turn match frame rate back on, but for now it's a happy compromise until Apple improves tvOS performance.
Thank you! Turning off match frame rate worked for me for a little while, even on 4:4:4, but then eventually started dropping frames again. I'll keep it on 4:2:0 with frame rate match off. I wonder if this has to anything do with the specific TV being used, but I don't feel like testing it any more. There is definitely something not working with the way the ATV match works. But your settings are working great for me! Even switching between Netflix, Amazon, and Channels. Going to keep these setting for awhile. Will try the frame rate match again at a later time when I am actually watching something not in Channels.
I think it's some bug/instability with the newer tvOS versions. I don't remember ever having these problems with early versions of tvOS 14 and I've had these issues with both generations of the Apple TV 4K, so I also doubt its hardware-related. Regardless, I'm glad it's working for you now!
I think the issue might be unique to the TV. But I have ATV 4k (v1) hooked up to a Samsung in one room and another ATV 4k (v1) hooked up to a Vizio in a different room. The Samsung works well on 4:4:4 with range and frame rate switching. The Vizio works best on 4:2:0 and can sometimes drop frames if frame rate switching is turned on.
I'm not saying its a problem with the TV. But it could be related to a tvOS update that caused the incompatibility. But its only on one of the two 4k TVs. Regardless, the default drivers work. Thats probably the most user friendly workaround right now.
Could also be an issue with the HDMI cable, to do 4:4:4 you need a lot of bandwidth and a high quality cable.
Maybe. I had actually thought about that too, but just was lazy to get around to the back of the TV. I was using an ultra high speed HDMI rated for 8K video. Maybe its stopped working so well. Thats would be strange, but I have a few extra HDMI. I just found one that says "High Speed HDMI with Ethernet" on it. Trying that one now. So far so good. But the other one would seem to work for some periods too.... so need to test this different cable for awhile to be sure.
But this alternate cable is working great so far. On 4:4:4 with both range and frame rate matching. @tmm1, that was a good suggestion.
Maybe just the cable wasn't the full solution. This seems to happen or YCbCr not all the time, but sometimes, after playing "The Grand Tour presents...", an HDR10 show on Amazon for a few minutes and then switch out of the app by pressing the home button. This causes the screen to turn black for a second and then back to ATV home screen. Then open Channels. And then some channels will drop frames, sometimes.
I then tried switching from YCbCr to RGB High, and Channels stopped dropping frames.
And then go back to play Grand Tour again. And switch back to Channels.... still not dropping frames.
Play some Dolby Vision Netflix, then HDR10 Amazon, then Channels. I have now done this full cycle of range + frame rate switching at least 4 times now on RGB High with the alternate cable.
And still no dropped frames. So I still think this might be specific to the TV along with the cable used.
So now I have found a setting that allows 4k full HDR + frame rate switching + no dropped frames in Channels. Will keep it on RGB high with the alternate cable. Hopefully this issue doesn't creep back again.
Btw, this is the short cable that was replaced:
