...attached you can find the incriminated cover (color is because Note is from my girlfriend ....even if I have G-Note too!!)
As you can see the magnet (I have removed it from the cover) is not big (thickness is something like 1mm). Approaching it to steel, it starts in exercising force at approximately 0.5cm!
As additional info, no problems were existing by writing with fingers! The issue is with S-Pen because the magnet interfere with it!
Here also the link where I could find my way out!....
....sorry..it seems it is forbidden to post external links!.....
I'm attaching an additional picture from this site with issue similar to my one, but bigger area (mine was something like 1.5 cm and located exactly on top of the clip)
here are the available colours: