Yes, it fixed the problem. The cylinder stop bolt is pushed into place by one of two fingers on that leaf spring. The other finger provides tension on the trigger. Because the bolt needs to respond up and down relative to what the trigger does when the gun is cocked, it makes sense to accommodate both with the same energy source, which is in effect modified by the working of the trigger.

So, the failure, on my part, to tighten that screw would cause the pressure on the bolt to be inconsistent with what is required by the system mechanics.