Good job on that fast rooter. You're doing it right and like everyone else stated don't panic the slower ones, they'll root....
I've learned sterility protocols are a must , Rose.
Pre-sterilized horticultural or surgical scalpels and iso cleaning intermittently between cuts. No industrial, bulk/blister packaged razor blades. They're coated in oil that even iso can't get rid of.
That and a low-N containing media cut w/ perlite for improved soil aeration...