youtube videos not displaying or taking edits well

I am editing a page that has many youtube links to videos.

It seems like every time I make a change to text on the page (not the youtube links) the display of the videos gets all wonky. Either the video box doesn’t show up at all, or reverts to just the text link. Or sometimes they will all align to left. I’ll try to center them with the editor and then they revert to links not videos again…

Are there some basic ‘shoulds’ for using youtube links? Is it best to use the url from the toolbar or the ‘share’ link? Does it matter?