The only 3 content types that remember (save) the title code you insert are:

• DTP - Video Embed (for Videos)
• Video - Video with Text (for Videos)
• DTP - Code Only (for Forms)

Any other content types on your website that have existing embedded code will not save any additional code you enter. For example, if you have embedded a video from Mediasite or Youtube into a 'DTP-General Content' layout, when you click Save Changes, the code is stripped out of the HTML and is not saved. Only certain content types are built to retain any additional code that is inserted. This is why your iFrame title has disappeared.

To solve this, you will need create a new block of content on the web page using one of the three content types listed above, embed the relevant code, add a title and then preview, save and approve the content.  You will also need to remove the existing embedded code from the other content type. 

View our video on how to edit iFrame code