Ok, stop me if you've heard this one and I just can't find the option.   I use the emby app on my android tv.  I also have a ton of files/folders that have internal subtitles on things.  The only weird thing is when it was initially transcoded for some reason they were lazy and the english sub isn't labeled as eng, its just labeled as UND (undeclared obviously)   it would be great to set it to play this as well as english (which I have it set for) automatically.  Am I missing it?