subtitles in windowed play

hi all,
I’m currently working on python video plugin that is like shell on top of everything. Currently I’m testing it on Kodi 17 with Confluence, on Librelec beta on MXQ box.
Plugin is working only when player is called in windowed play, without windowed play plugin is starting again and again everytime when new stream is called to play.
So, to the case … when player is in widowed play there are no subtitles shown, is there any chance to show subtitles.