How could it reasonably be considered a "normal function" for two parts which ordinarily have no mechanical interaction to be violently gnashing themselves together, leaving a gouge in the barrel which ought to tell any engineer that something is not right and needs correction?
My guess is that Walther's engineers long ago identified the flaw, but management told them to ignore it. It's cheaper to declare that it's
“And that’s why I sold my Sig p365 and have a m1 (Classic) Walther PPS and not the M2 version. Plus I like a paddle mag release. I had zero love for that p365!!”