1) STI sold the company to new owners.
2) They brought in two very talented gunsmiths, Dave Dawson and Shawn Armstrong (lead gunsmith at Nighthawk prior to Stacatto) and actually listened to them.
3) Re-designed the magazines, and most importantly outsourced the production of the new magazines to a company that specializes in making magazines resulting in a consistent product.
Previously, STI magazines were made in house by means best described as “Geptepto’s workshop.” if you saw how the STI magazines were made, it’s no surprise that some of them worked and some of them didn’t unless they were tuned. I.e. brought back to the proper dimensions and specifications.
There’s a reason why most major gun companies, Beretta, Sig, Smith & Wesson etc outsource most are all of their magazine production.