Youtube Video size is not adjusting like before

Hi there heroes! I really need some help with a issue I'm experiencing.

Today I've realized Youtube Videos on my website (using [embed] shortcode) are not being adjusted to the with of the element.

You can see what is going on here, scroll down to see you the full videos list:

I'm not sure if any Plugin was installed but I believe not. Maybe this could be related with some Wordpress update I missed?

I would really appreciate some tips on how to solve this asap. Thank's!