When the PX4 .45 first came out I was among the first to get one. It suffered from the Failure to go to Battery after 50 rounds consistently. I put 2,600 rounds through it and sent it back to Beretta twice. They could not figure it out. They refunded my money.
I went back to the PX4 Full sized .40 for years and was disappointed. Later, I tried again and got a flawless .45 Storm (my current EDC) It was so good that I got another one later for beating up on at the range and training. I called it my .45 SD (Stunt Double). Later, they started making an actual SD!
My point is that back in the beginning they did not know how to fix it. They learned through time that .45s are a breed of their own and needed a certain tweaking occasionally. So many came back at first with that issue that they knew exactly what to do about it. 1911s often are sensitive to loading issues due to extractor issues. My thought is that the diameter/length ratio of .45 is very different and needs to be set up accordingly. Now Beretta knows exactly what to do if you want to try again.
My shooting partner's .45 SD (actual Special Duty) suffered from that and they fixed in a couple of weeks.... flawless performance ever since.