I'm slightly confused about threads, thread drawing conventions and the way inventor handles them.
Attached is a simple pdf example.
So here I have created a simple threaded hole and threaded screw (both with the same thread). I would expect the thinner lines (for each part), highlighted in breakout 'C' to be colinear. It is my understanding that they represent the major diameter for the inside (hole) thread and minor diameter for the outside (screw) thread?
The way the drawing looks to me is that the screw would just freely pass through the hole without engaging with the thread.
I'm not a mechanical engineer by the way
First thing to try is to measure or dimension the diameters of the screw and hole to see where the error is. My guess is that the hole is shown too big due to the .ipt file Document Options > Modeling > Tapped Hole Diameter being set to Major instead of Minor.