There is no association between the serial number prefix and the particular problem you are experiencing however the choice of ammo could be an influencing factor - I might have missed it but I didn't read where you identified the brand.
If you have not done so already, call Ruger in Prescott. More than likely they will issue you a prepaid mailing label and advise to send the gun back. Prescott's turnaround time is very fast normally. However.....may I suggest that before you do that, you ensure that the gun is sufficiently clean and lubricated and, I would give it another range test before opting to box it up. Tolerances on this gun are fairly tight particularly when new and it is not unusual for there to be something of a break-in period before things settle in. Not always but sometimes.
An excellent break-in lube for the rails and metal to metal contact points is Brian Enos' Slide Glide Lite, a low viscosity grease that stays put and is specifically designed for carry weapons - I have found over the years that it also reduces wear extremely well - and I highly recommend it for the LCP for the first hundred rounds or so (I have no business association with the company, just a user). And, don't be afraid to slingshot that slide (to chamber the first round) with "conviction." You are not going to hurt anything.
Finally, although you may not feel comfortable doing (or feel you should have to do), many LCP owners have benefited from a little light polishing of the barrel feed ramp and chamber (before the rifling begins) to enhance feeding and reliability. If done correctly, it is both easy to do at home and will in no way warm your weapon or void the warranty. If you are not comfortable doing/trying any of this and you continue to have a problem (and with a variety of factory ammo to rule out brand sensitivity), then the gun should be sent back to Ruger. As not to re-invent the wheel, here is a good "how-to" on LCP barrel polishing for those interested: