Wierd bug

Hi y'all,
I seem to be have a wierd issue with youtube videos on the site. For some reason, The embedded videos on the site do not have a fullscreen button, or option. I have to go on youtube to watch fullscreen.
So I don't know if it's on my end, but I don't think so. Is it a new feature youtube implemented? Or is it the way the videos have been embedded?

If anyone could help me, it would be greatly appreciated.
Sorry if my english isn't perfect, I'm french (excuse my french...)