Apologies if this is not a new topic. When using the S Pen I SOMETIMES found it would not work on a small square of the screen although the screen would respond to my finger. I contacted Samsung Support who are now in the process of sending out a new S Pen. However, I have now found a solution. My case contains a magnet in the catch and a magnet in the back cover. If I flip open the cover AND tuck the catch behind the cover so that the two magnets align this causes the problem. A quick fix is to untuck the catch then rotate into landscape and back. Hope this helps other users.