Subtitle deselection when switching apps

when I select subtitles with a%2B in its name from downloads folder and switch to another app after, when I open vlc again the subtitle dissapears and I have to load it every time I switch apps.

Also, why is the player divided in two apps when I play a video? One is the app itself and the other one is the player, if I switch apps while playing a video, it opens the last app I used when the video finishes, and not the vlc menu for next video selection.