Rather than guess, you can do the math.

It sounds like you were 90° off.

90° less? Or 90° more?

What is your thread pitch?

How far in does the head of the screw go in 360°.

A piece of feeler gauge approximately 1/4 in thickness of that distance should give you a very accurate shim to place under the top strap if you want to.
No machining, just a pair of scissors.

Out there doing it best I can.