Moi has been having trouble finding points to snap to. Specifically on surface edges. I always have to draw a grid line to get the end snap to show up on very basic geometry. The On snap always works, but when I get to a corner it can't find the End or Intersection. All snaps are turned on, I will reset the view on the object, and it never works consistently. Any pointers? Also is there a way to lock a direction something is drawn?

Thanks