Subtitle list panel disappeared

When I started using the Chrome extension, the side panel containing all subtitles hid the right part of the movie. Somehow I managed to hide the panel.
Now, the movies, full screen or not, have a black part on the left. So ugly. I cannot get the panel back.

I want to have a panel that doesn’t hide the movie. I want to be able to toggle the panel. When the panel is hidden, I don’t want parts of the screen to be black.

Hi, what operating system are you using? Do you have any other extensions installed? Is this on Youtube or Netflix?