Rengan77.
I just checked out your DXF for the chess pawn. Your profile is made up of generally individual polyline segments. This could be an issue, as the direction could be random, and possibly the odd gap in the profile. Much safer to join all segments required into 1 continuous polyline (No gaps, and all going the same way) as the Follow polyline functions do not correct direction.
Also split the big arc at 0 and 90 degrees to remove the unwanted part, and to allow Ezilathe to truncate the cut as required.
Parted it off for you as well. The head will still show a slight undercut from the tool radius and 11 deg lead angle. you would be better off with a sharp knife tool with no rad and 0 lead angle.