Hi I announced a bug several days before .2.3.0RC3 was released in the .2.3.0rc2 forum. Unfortunately the bug is still here. Please see this post for more information
https://forum.team-mediaportal.com/embedded_srt_subtitles_ogm_not_show_up-t29603.html
https://forum.team-mediaportal.com/embedded_srt_subtitles_ogm_not_show_up-t29603.html