With server 3.3.1.5, when an embedded subtitle is selected before play, strm content (with embedded + external subs) is direct playing and shows embedded subs OK.
When subtitle is switched during play to a srt, the movie reverts to direct streaming and ffmpeg kicks in, but fails to show the srt subtitles. Comparing with local movie content that is direct playing, switching to srt never changes to direct streaming.
Also when an external srt subtitle is selected before play, Emby theater never shows the srt and plays the default embedded subtitle track instead.
Webapp plays srt fine with strm when selected before play, in case you would ask