Star Wars movies wont play properly

I really would like to watch all the star wars movies with my new surround sound but they dont play properly. They video and audio stutters. Is there anything you guys can think of that I could possibly try?
It does this on both PC and my TV app ( plex )

What information is showing in the “now playing” tile for that playback on the Plex server dashboard? Specifically… is the stream listed as local, remote or indirect? Any transcoding going on?

Exemplary screenshot from the "now playing" section
https://support.plex.tv/articles/200871837-status-and-dashboard/

Yes there is !
That would be the issue

Is there a way I can encode this file so it plays native? Its the audio. I have a sonos 5.1 surround sound system so want to keep that if possible . Its the main reason I want to watch it
image

Try the app

https://www.plex.tv/media-server-downloads/?cat=plex+desktop&plat=windows#plex-app

Sorry I told a lie with my above screen shot of the dashboard
That was playing on my PC

I did try again on my TV which is where I want to watch it but both are direct play both the video and audio

And it says aac 5.1
That’s not surround sound is it?

Either way I’d still like to watch it without all the stutter

It’s a 6-channel audio track – usually that’s 5 tracks for the regular speakers (front-left, front-center, front-right, back-left, back-right) and 1 subwoofer track.

What exactly is stuttering? Audio, video or both?
Do you experience the same with or without the Sonos connected to the TV?

6 Mbps is a very low bitrate for a 4K movie.

Netflix streams 1080p at 5 Mbps and 4K at 20 - 25 Mbps. Blu-ray disc rips run at 30 - 40 Mbps for 1080p and 40 - 100 Mbps for 4K HDR.

Might the file itself be causing the problems?

Do you have other 4K movies/shows that stream OK?