I had some teething issues with my px4cc when first got it. Mine is a base model bought from Robar when the first came out. I had failures to feed at first as well. I accepted it as a break in period and continued to shoot it but I also looked into possible causes. First off I noticed a burr on the plastic near the top of the feed ramp. I cleaned it up gently with some emery cloth as noted in this pic:
The second thing I did was disassemble all of my magazine and cleaned them with dawn dish soap. I remember reading I think somewhere in this thread that there can be some gummy residue left from the factory in the mag body. Sure enough they needed cleaned. After letting them dry out I sprayed the inside of the magazine with dry Teflon lubricant, I’m not sure it was necessary but I didn’t see how it could hurt.
Thirdly, I noticed that my thumb position while shooting was causing some drag on the slide. I adapted my grip slightly to avoid touching the slide.
I have not had any failures to feed since doing these three things. I will also note that my px4cc does not like steel case ammo at all, it will jam in the magazine consistently. I rarely shoot steel case ammo anyway so this is not as issue for me. Hope this helps, a new gun that doesn’t run well is frustrating. Let me know if you have any questions about any of the above.