I have a Samsung Smart TV Tizen version 2.4.0, Plex App version 3.2.2. Plex Server Version 1.11.3.4803
Whenever I play a file with an HEVC codec the video stutters almost immediately.
When I view the activity on PlexWeb it shows the file as Direct Play. The file has a supported video and audio stream and no subtitles were selected. I ruled out the possible limitations(Video was not transcoding and the CPU usage was low, connected to network with a wired connection so bandwidth wasn’t an issue).

I decided to try the file through the DLNA server to see if it was an issue with the app, file type, or the TV. At first it would not play because the current DLNA profile provided by plex (Samsung SmartTV) was incompatible with the TV’s supported video and audio codecs and would try to transcode. I deleted the profile and confirmed in the DLNA Logs that Plex was then mapping a generic profile. Once this occurred, the video would direct play without any issue.

You won’t need to give one of the HDMIs over to a dedicated streamer, because the TU7100 gets the same Tizen operating system as Samsung’s flagship sets. It’s absolutely packed with apps, including Netflix, Amazon Prime Video, Google Play Movies & TV, Rakuten, Disney+ and Apple TV – all in 4K and HDR10 ( HDR10+ in the cases of Amazon. There are probably some additional playes in the App Store (Such as Plex). I personally still have an older Samsung TV without Tizen so unfortunately I can't make more direct recommendations. But I'm pretty sure that there are some in the store. The app is available on 2016 and newer model year 4K/UHD Samsung sets that are Tizen-based. The exception is for users located in China or Iran; the app is not currently available for users in those countries. No 720p or 1080p (“full HD”) sets are supported for our current app at this time. Related Page: Tizen-based Samsung TV models. Build Tizen.NET apps running on millions of Samsung devices around the world. Learn about Tizen.NET to develop your applications for the Galaxy Watch. 272 votes, 89 comments. 182k members in the PleX community. For questions and comments about the Plex Media Server. The Plex Media Server is smart.

Is there something I am missing? Does anyone else have issues playing 4K videos through this app?

Samsung Tizen Plex 2

Media Info

Video
Codec HEVC
Profile Main 10
Level 153
Resolution 3840x2160
Aspect ratio16:9
Anamorphic No
Interlaced No
Framerate 23.9760246
Bitrate 66125 kbps
Pixel format yuv420p10le
Ref frames 1

Samsung Tizen Plex 7

Audio
Language eng
Codec AC3
Layout stereo
Channels 2 ch
Bitrate 320 kbps
Sample rate 48000 Hz