Plex stuttering on Apple TV

So when I run files from my Plex server I get stuttering in the image every 5-10mins for a few seconds. It doesn’t effect the sound and the app doesn’t give the buffer wheel. It just stutters or jerks then will smooth back out. This only seems to be an issue with 4k 10bit videos codes in h.264 or h265. It doesn’t seem to make a difference if it’s mkv or MP4. And it happens in files with bitrates 15mbs or 45mbs so seems to be exclusive of bitrate. I assumed it was a Wifi issue but despite switching to a wired connection it still happens. And on speed test with Apple TV wires running 1gig. I also tried infuse app and while the stuttering was definitely less it still occurred. Also have seen that subtitles can sometimes cause compatibility issues but this occurs with them on or off with similar frequency. When I run the Plex on my iPhone 12 I haven’t been able to replicate the stuttering issue even over Wifi. I’m out of ideas. Does the Apple TV 4K not fully support the 10bit? I mean it says it does but I can’t think of any other ideas.

NAS run off a synology 920+ with IronWolf drives in Raid 5 with 8g of memory and 1TB cache ssd. On the Plex server it says it’s running 30-40mbs with occasional spikes but nothing above 100mbs. It’s all direct play with no transcoding. The NAS never runs no more then 15% utilization of memory or 10% CPU on its resource manager. The Apple TV is brand new 4k with os 15.2. Tv is new Samsung Qled q80.