Dissapearing phrases when exporting .STL Subtitles

Hi everyone,

I'm having this weird issue when exporting subtitles in .stl as a sidecar file: some subtitles are completely omitted (Some of them included a Ñ, that could be it?). Also, some subtitles that should be on the top right cornen are shown on the bottom third, how can i solve it? (I'm testing them on VLC).

thanks