OK, thanks for the breech face pics. Yours looks normal.
I think I have the answer. Take a look at these pictures:
The first picture is how the chamber should look when ready to fire. However, the second picture is with the slide back a tiny amount. The arrows are pointing to the chamber and how it's just a tad lower than the slide. Even with the slide back and the chamber lowered that tiny amount, the striker can still be released. Move it back any further and it won't release the striker.
While not fully in or out of battery, the chamber is lower than it should be when firing the gun. This condition will cause the off center strike you're seeing.
The Shield has been known to not go fully into battery when new. If a chamber check is done, the slide doesn't always go fully forward under just the pressure of the recoil spring; it must be pushed forward.
So, what I believe is that the slide is going mostly forward. You're pressing the trigger and feeling the click of a released striker. It is indeed hitting the primer, but off center because the chamber is down just 1/32" which is about the distance you're primers are off center.
There you have it. It's the only explanation I can come up with for what you've shown us. My assessment of the situation as it stands:
- It is not unsafe.
- It will clear up with use.
Of course you could send it back to S&W. That would be prudent. I can't tell you for sure without seeing the gun myself, but I'd just keep shooting it. I'd clean it out with a fine tooth comb and examine the function like it was a crime scene (meaning thoroughly). In the end, I'd just shoot it.