First of all, welcome to the Forum. Some folks have claimed/seen IL lock failures where the gun becomes inoperable. Seems to be an issue with the ultra lightweight models ie scandium.
I have 1 locked gun, a S&W M500. If they made one without the lock I'd sell it. The issue to me, is asthetics, they put the lock in a horrible place. I would have preffered, other than no lock, that they hid it under the grips.
Some buy "the plug" and replace the lock. IMO, and my opinion only, it still locks awful.
You could have gotten a brand new 642 without the lock also.
Take this all for what it's worth.