More than 5 videos in a webpage results in remaining videos converted to a button

More than 5 videos in a webpage results in remaining videos converted to a button - The button is labelled "Edit Button" and the hyperlink to the youtube or vimeo video is in the hyperlink. Replacing the buttons with the video works and can be republished. If I try to re-open the video for editing, the videos are converted back to buttons. There is no "webpage" topic in the list below, so I have chosen "add-ons"