I can reproduce this over and over.
I have an admin and I have an Author.
admin can post embed codes in the html tab (I disable the visual tab for everyone) and the author, when they post an embed code and hit save, the embed code disappears.
I have this problem too, now even with the latest version of 2.8.2.
It only works if admin directly embed and publish the youtube video, and not to use the “submit for review” function.
