Something I've noticed lately in the newer CC versions of Illustrator is the pen tool is "snapping" to other paths/objects when I get my tool near to it.
For reference, I have ALL snapping features off. My selection tolerance is down to 1px, I have rubber band turned off for the pen tool. It shouldn't be going anywhere other than where I have my pen tool hovering, yet it's still jumping around.
I'm specifically noticing it when I need to be zoomed out, because I'm going to be adding anchors over a large area. I thought maybe it was my Wacom tablet cause I've had so many issues with it since updating to 2017, but I'm starting to think this is just a really crappy version.