Update -
So i did a few changes in wiring - all new cat 6 Ethernet throughout - had to be done anyway and I also bought newer HDMI cable that were also very old - so everything wired is more up to date.
Had time to cable manage too 
I was hoping this would help my “bandwith” problem and it did not and does the same as before - once files have sound file DTS MA it struggles and when I try a video file above 1080p so 4k it struggles.
Not sure if it will help anyone if i add my log file here to identify the problem - i tried to eliminate on my side all but still no luck.
I added my log here - you may notice many files played as downloaded a few demos to test, maybe somewhere there there is a problem someone can help me with.
One difference - DTS MA files for example just skips when playing and has a delay to reach my AV amp to show DTS.
If I play 4k files regardless of sound file - it skips and I also get a message not enough network to server to play this file - BUT at 600megs going to my server I cannot see this to be a problem.
I checked CPU - RAM usage and both do not struggle.
Please let me know which Log file you need - thank you instead of sending the whole zip file.
edit actually found the recent changes in the log when trying a few files this AM at 9.40am in the logs
com.plexapp.system.log (14.0 KB) Plex Media Server.log (5.7 MB) Plex Transcoder Statistics.log (5.8 KB)
another edit maybe -
My current server set is:
Thanks.
