I had issues like this when I had manually recalibrated the pen(not talking about through Surface Hub). I am not running Windows 8.1 anymore, so I do not remember how to open up the calibration, but I think it is called Tablet PC Settings.
It brings you to screen where you tape 4 points with the pen. you can set it to factory default and that might fix issue. When I calibrated it myself, there was part of the screen that if I was near it the cursor went crazy. Just resetting it to default fixed issue.
It brings you to screen where you tape 4 points with the pen. you can set it to factory default and that might fix issue. When I calibrated it myself, there was part of the screen that if I was near it the cursor went crazy. Just resetting it to default fixed issue.