So I have been using the Surface Pro 4 since it came out, main issues I have had were, touch screen would randomly stop responding (touch or pen), but I would just restart and everything was fine. Also, from time to time, the Surface would not come back up from Sleep and I would have to hard reboot (power + vol up), unfortunately still happens after all recent updates to accommodate Skylake issues, but rarely.
However, a friend of mine recently got a brand new SP4 and started using OneNote, both the Metro preinstalled one and OneNote 2016 Desktop application. Completely randomly about an hour into using OneNote, touch and pen inputs stopped responding. But the weird thing about this was that I could see the touch & pen inputs register on the screen, but they would not do anything in the software. The only touch input I was able to register was the Start Menu to open new apps, but I could not close them by touching the X at the top right. Really weird that I could not register inputs other than Start Menu button. Once I restarted, everything was fine, but its really weird, I have never seen this on my own Surface, but I dont use OneNote too much either. So I only assume its OneNote related. This has happened twice on my friends machine when using OneNote. He also has all current updates. But the big difference between my issue and his was that my touch screen just stopped working, there was no visuals that the SP4 was even accepting the inputs, where as on his, I see all the visual cues that the SP4 was accepting the input, but nothing happened, only Start Menu responded, until I restarted. This was brand new right out of the box after the required updates too.
Any ideas folks?