Size of video

All Youtube videos embedded with this plugin always expand to the full width of the cotainer, even though this feature is disabled in the settings. What could be the reason for this?

Here is a page as it should be (video embedded with another plugin): https://www.prairiewind.ch/native-american-webseite-fuer-den-webby-preis-vorgeschlagen/

And here a page with the error: https://www.prairiewind.ch/?page_id=12246&preview=true

The page I need help with: [log in to see the link]