Put a magnet near the front of screen and try to use spen

I'll try it in the name of science, but I've never encountered this. What is your use case? In the 13 years I've been using Wacom stylii on phones and E-ink devices, I've never encountered this.

Put on a 3rd party wallet style case with magnet that keeps it closed. Parts of the screen near the magnet stop responding to spen for a time.

Just tested on Note 8. Put magnet on the back of phone and area about 10 times the size of the magnet stops working with s-pen