I have LG 43UJ620V and I've been trying to play video in mkv format streamed via DLNA, subtitle file is in .srt format in the same folder as the video and with same name.
But the TV doesn't show subtitle. However, to play the same video from a USB, TV perfectly reproduces the video with subtitles.
I'm running Rygel from Ubuntu 18.04 LTS.
I wonder if there is still no support in WebOS for external subtitles via DLNA.
Nevermind. Got it. Support for external subtitle was added in most recent code of Rygel.