According to the civil law suit papers, this has been known since 2008 with documented cases involving Sig pistols. The new model P320 is the latest. All are stated in the 12 page civil suit document. It's an interesting read and should shed some light on this alleged issue involving the P320 set up.

Case: 3:17-cv-01318-JCH filed in USDC of Connecticut on August 4, 2017.