There is a rare bug and there are two ways you can fix this. The first is to do a hard refresh on the booklet editing page. For a Windows based machine, hold CTRL and hit F5. On a Macintosh machine, hold Command and hit the "R" key. This will refresh the cache on the page and hopefully allow it to register the edits.
If that doesn't work, you will have to use the "Reset to Default" option in order to get the Author Page to save any edits you make to it. Our apologies for having to redo any edits you've made to the body of the booklet.