Facebook Container dev here. It breaks those sites because the extension blocks all Facebook resources (and tracking) from loading on non-Facebook sites.
To use Facebook login on a site, you'll need to add the website to the Facebook Container. Follow the directions from the docs[1]. This will stop you from having to turn the extension on and off entirely.
To use Facebook login on a site, you'll need to add the website to the Facebook Container. Follow the directions from the docs[1]. This will stop you from having to turn the extension on and off entirely.
[1] https://github.com/mozilla/contain-facebook/blob/master/docs...