Hi Guys
So I don’t know if this will work for you. But I did some testing on the top down template. i made it so that my clicks had to be 100 Y and 100 X apart. This should have made the character always stop in the center of the grid.
As you already know he doesn’t. But by putting the current character location on the screen I noticed that he always stops 81 away from the click point…
The solution that worked for me was to change the [ROOT] CapsuleComponent on the character to have only 1 Capsule Radius instead of the default 41.
Now he stops in the exact location each time. 
I am guessing that it you need the CapsuleComponent put it someone apart from the root and you should be fine.
I hope this helps
Andrew