I've noticed ever since updating to 5.80.xx (and I got the second OTA update last night) that I've had motion issues, all on non-24p content (like sitcoms). There is a constant stutter, almost like a frame is missing every 5-10 seconds. My panel and main board had been switched out before thanksgiving, but the issue really presented itself to me over the past couple of weeks.
I tried a different HDMI cable. Didn't work. I tried changing the frame rate option under the video settings on my Apple TV 4K (which I have set at 4K SDR 60 btw) - I never used it as "on" before, just used the "range" option. Interestingly, once I changed the Frame rate to on, it fixed the motion issue (this setting forces the AppleTV 4k to output content in it's native frame rate instead everything at 60hz). Since I'd never had to use this option before, I unselected it and started to make adjustments to the TV settings.
This is what I found out:
All of the motion settings are always turned off in my TV settings and "Real Cinema" is turned on by default (I'm under the technicolor preset, btw). On non-24p content, the RealMotion setting is causing this frame stutter. As soon as I turned it to "off" the stutter instantly stopped. Also, If I enabled the "user" mode under motion settings and set everything to "0" (which greys out realcinema) this also resolved the stutter. Never once had this problem before (and my Apple TV hasn't gotten any updates in the past couple of weeks to cause this). It's almost like the TV is applying the RealCinema to everything, where it's only supposed to detect 24p content. Seems like it's adding processing and not detecting 60hz properly.
Anyone else noticed weird issues like this?
Also, side note: I had a ton of drama a month or so back with HDMI cables - I had Monoprice premium certified 15ft cables run through my wall for 6 months and then randomly started having ton of handshake issues with my ATV4K - image would randomly cut out, show static and then go to "no input found". Instead of calling an installer back out, I just attached my apple TV to the back of my TV with command strips and I'm using the Belkin 6ft 48gb bandwidth cable that apple sells (but I got it through amazon). No handshake issues and I've been running at chroma 4:4:4. I also bought an amazon HDMI cable and I tried that as well, 6ft, and had no issues. However I'm using the Belkin cable since it offers higher bandwidth....juuuust in case. Also the 15ft Amazon cable which I was going to have the installer use had I chose to go that route, worked fine at 15ft - no issues. Just thought I'd put this info out into the wild in case anyone ever has handshake issues with the ATV4K.