Failure to feed - Zaffiri OPMOD MG9 Glock 43/43X Flush & Crown Pistol Barrel

First time shooting with the new barrel using new 115gr FMJ ammo. While shooting 20 rounds, I experienced 8 random Failure to Feed jams where I needed to assist the slide in chambering the round (the round loaded halfway into the chamber). I put the original barrel back in and no failures. I put the Zafiri barrel back in and tried a different brand 115gr FMJ bullet and had the same issue. I have never experience a FTF failure in the 5 years I have owned this handgun. I will try polishing the feed ramp to see if that helps. If not, the barrel is unreliable and should not be used for anything but plinking.