AIB

Strange. It is now working. What I did was having a factory reset, then upgrade to Ultimaker 2 Extended latest software with an older version of Cura (v15.06.03), then using the latest version of Cura (v3.4.1), all Windows 10... wola! I think this is the way to fixing this problem for now. One thing to take note of: Upon both upgrades of the firmware requires leveling of the buildplate. This signifies all of the upgrades are fresh. Hope it helps!

Yes, I am having the exact problem, too.

I agree. Start printing with PLA is much easier. I am not sure about 70 degrees this high with XT, while my very workable setting with average PLA is 210 degrees with a heatbed of 60 degrees. My last sharing is that small objects of say finger-size in height and less than an inch in diameter appears very sensitive to heat, even to a degree or 2 of adjustments differs a great lot. Hope my 2 cents helps. -Gidi