Thanks for the reply, @julian!
Yes, I've tried using "ns-" plugin as well, but I had even less luck with it: it even doesn't show in the "Plugins" dropdown menu (cannot access plugin settings page).

you can open an issue on their issue tracker.

Are you talking about the Github issues section? Or there is another place where I can post it?

P.S. The issue with the ns-embed on Github: https://github.com/NicolasSiver/nodebb-plugin-ns-embed/issues/29