.sub subtitles not working in movies

I have problem .sub subtitles does not show up at all in subtitle menu in movies but tv-series (in different folder) works fine with subs. Subs works fine with other player, movies are .avi and .mkv files. All files are playing from smb-shared disc. All subs are renamed to match with movie files. Thanks in advance for your help.

Unfortunately .sub files are not yet supported, though these will be added in a future version.