iprofun
Member
I also encountered this issue as others have reported on reddit and in Apple's discussion forums.
What's been determined is that the issue was introduced with iOS 9.2 and that it does NOT occur with the Apple Pencil.
All the iPad Pros may be afflicted with this, but you'll only observe it after upgrading to 9.2+ and by using a normal capacitive stylus or very light touch with your finger.
I doubt that the issue started after upgrading to 9.2 since they my two Ipads had the same problems before returning them and restoring them to factory settings. I had to show them the problem before returning, and they were back to pre-purchase condition. They don't seem to acknowledge that this is an issue, they only talked about the screens going dark, but have not made a statement about the dead spot.