I am using CK editor 4.4.6.
It seem on the first instance of pressing shift + enter, the editor inserts an invisible character. Upon submission, the character saves as a question mark. I can't see the character in the form submission when viewing the debug in the browser or the source code in the WYSIWYG editor itself. I do however notice when I press the right arrow that the cursor pauses at this character even though I can't see it. The page is being served in UTF-8.