Why don't I have video subtitles when when using other Explorer?

[AC Question]

No video subtitles when when using other Explorer

I have a simple HomeBox 3.1 mediaplayer with Android 4.4.2. My video files and subtitles (-.srt file) are on a local NAS. When using the standard Explorer subtitles are displayed correct using VLC (0.9.2) or Kodi (14.0). But this explorer does not display files in alphabetic order.

When using ES File Explorer (1.6.0.4) or Total Commander (2.50 or 2.60B2) with TC-Lan (2.08) filenames are displayed in alphabetic order, but subtitles are not displayed.

Any suggestions ?

Thanks Henk.