Video test post

I’ve been having a few issues with videos. This post will test three different options for putting youtube videos into a blog post.
It really shouldn’t be too difficult.

Method 1.
The one I’ve been using for years.

Method 2.
The one that WordPress says should work.

Method 3.
The one that seemed to work on this post.

UPDATE: For me, only (3) is working in Chrome. (1) and (3) working in Firefox.
Anyone else?
Colour me confused.