Sad to say, it is not a very recent phenomenon.
My M640 .38, bought when I learned they were going to .357 Magnum in steel J frames, which would have been in 1995-96, is flawed.
The cylinder flutes are not centered between the chambers.
Embarassingly, I never noticed until after I had the gun engraved and the pattern emphasized the misalignment.

Not as bad as the poor guy who got a 686 with seven shot cylinder having six flutes. Or was it six shots and seven flutes. Either way, it was very strange and formed some very thin chamber walls. They replaced it, of course, but he was still disgusted.