You are working with a very small bolt. It could be in the accuracy settings. Try changing the pitch to a larger value and see if that lets it work.
In general, these work as expected but sometimes it gets lost. Is the value of L1 the same as the pitch? This can cause issues and can be resolved by stepping the triangle outside the bolt face and increasing L1 but manage the ID of the cut. This will create an overlap in the spiral but will eliminate the tangency issues.
The trajectory is simply a guide. The axis is a key element. Just know how your sketch will interact with the trajectory.
When I define a bolt like this, I try to leave the appropriate flats. Making the widths of the flat the same inside and outside is the challenge. The theoretical sharp of the thread is always slightly larger than the specified screw size. Below, the pitch is also .8:
