insert/edit media as instructor not working ( 1.6.12)

HI

On 1.6.12, login in as instructor, on the course builder section, add new content, using the editor, if click insert/edit media button, put any youtube url (general), there, it will appear in the editor, but after you click save/update, the inserted video is gone.

However the above insert/edit media is working as an admin user.

Anything wrong?

thanks