Hey there! Sorry about the confusion.

In Firefox, the in page selection only changes the subtitle for the current episode. In Chrome, this opens the sidebar, but Firefox doesn't allow that :\

To enable/set the subtitles globally, you need to:
1. open the sidebar on an episode page
2. open the overlay options collapsible
3. switch the scope to "Global"
4. setting the preferred secondary subtitle (note it may not be available for every show)

The system is a bit complicated, but enables pretty cool subtitle customization from show to show. For example, you can have a different font, background opacity, size, etc. per show, or even per episode.

I believe the sidebar opening is kind of a Firefox quirk (not present on Chrome). It wasn't a big problem during testing so it was overlooked by me. I'll look into disabling it.

Thanks for the review!