[Zubersoft]

Everything looks fine as long as you aren't using the "Cut" option with the snipping tool. If you use that, then it's going to impact both instances of page 21. Instead, you have to use the square tool to just draw a white rectangle (you can save this as a favorite) if you want to white out a section of the page without it impacting other pages. This behavior changed several updates back because users were running into an issue if they cut something and then tried to paste something on top of the white rectangle. This used to be impossible because the pasted image would be saved in the PDF and would be drawn underneath the white rectangle. So the behavior was changed so that the white rectangle is also saved in the PDF so that pasted images can be placed on top of it. These changes impact all instances of a page though. 

Mike