Subtitle button?

This might sound utterly stupid, but where is the “change subtitle button” on the Kore Remote?? I am assuming it is the button in the left corner next to the navigational arrows, but when I press it nothing happens. I know the movie has subtitles because on a regular keyboard I can easily change the subtitles by pressing L. The Kore remote functions properly aside from this. I am using KORE on an android phone btw.