[Pen Tool unable to add new point near previous point]

I am trying to draw a new curve. I think this qualifies as a bug. What kind of pen tool is this when you cannot plant your next point close to your previous point. 

[Pen Tool unable to add new point near previous point]

I am using iPad Pro 9.7. 

In using Pen Tool, when the new point I try to add is in close proximity to the previous, I get a contextual menu of Select-Copy-Paste-Delete. Sometimes the app just simply refuse to add the point. Sometimes a magnifier-like circle comes up. What’s happening?