Is anyone experiencing a patch in the note page where the Spen does not write?

[AC Question]

I have a patch on the note page that will not show the writing of the Spen. I got my first Samsung note 4 last Tuesday, and got it exchanged today. This also is happening on the one I received today. Is this a fault with the product or programme?

 

[anon8380037]

Hello. Any chance it corresponds to a magnetic clasp on a case. That's a first thought.