So there appears to be a nasty video-embed bug, when using the built-in video link share button.

With this bug, the video image embeds itself in random parts of the post, behind other images even - and can move text around too.  I'ts pretty nutty.

                                               example of the video embed bug

One workaround I have found is to simply the embed URL and adjust the viewing box to a smaller size.  In this case, 720 x 405 seems to work.  It also helps to use the HTML markup version of your post (icon <> located in upper right)

                                     work-around for embedded videos.

A note of caution though, don't add video embeds until the very end in your post.  It will save you some cleanup work and headaches.