Same problem, on a SM-N9208 64GB Duos.
intermittently losing touch screen every few months. My method is...
1) While S-Pen is removed, plug-in micro-USB-charger (on at power source) whilst phone screen is on and unlocked.
2) Press & hold at exact same time Power & Volume Down, until the screen goes black then quickly release buttons & you'll see the charge screen animation.
3) Press Power & Volume Down again, releasing Power only once you see Note 5 Boot screen. Your Theme should change to default & on lower left screen corner it'll read SAFE MODE.
4) Unlock screen & repeat step 2)
5) Now your back to the charge animation. Press Power button & turn on device as normal, still all with S-Pen removed & Charge lead connected. Unlock screen, go to settings/themes change to another theme, set a different wallpaper too within the Samsung Theme system app.
6) Open Chrome & do an image search for anything 2560x2560. At this point once the search list returns the results, drag the screen down to refresh with the stylus & as you slowly drag & the refresh icon arrow turns in it's little circle slide your finger off the S-pen onto the screen. It should now work.
Patience & Persistence is key. Repeat if necessary.
It seems to be a firmware bug issue, like when some times you have to clear an app cache or cookies to get an app or website to work.
Try clearing Dalvik Cache a couple of times too, it can't hurt.
Hope this helps out others with Unresponsive Intermittent Touch Screen issues. ;-)