Hi.
I have Qnap TS-231 server with Plex installed, and 2 different TV’s connected.
TV 1 phillips with android, wifi connected, streams perfect with subtitles
TV 2 LG with Web os 3.5 lan connected, can some time stream without subs. if subs is added, failure coming up that server is not strong enough to convert video.
any ideas?
from your description it’s not so much about the network speed but about the capabilities of the different clients. TV1 appears to be direct-playing more of your content than TV2 which requires your server to transcode all/more content for TV2.
You can look at Plex Web during playback to see what is causing the transcoding (in Plex Web click 
and go to Now Playing… when hovering over the playback item, this should show the playback mode and transcoding details).
