Failed to feeds issue - Killer Innovations Velocity Glock 19 Gen 4 Slides

Having failure to feeds also feels ruff on the pull back..hope it's just a break in issue going to turn a few more rounds but for this price i wish it would run smoother..also I did not change out the parts of the slide myself took it to a blue labeled glock dealer....really hope it's a break in issue ..gun seems to run fine with hollow points