Shifting from 1st to 2nd

They say there are no stupid questions ;) Z900 is my first motorcycle (aside from MT07 on the course and a test ride on MT09 YAMT), hence my doubts: with KQS off, when I shift from 1st to 2nd gear at low revs then it's smooth, but when I do it at 5-6k rpm I hear a "clunk" sound, similar to shifting from N to 1st at a standstill. Is this normal for Kawasaki? I read somewhere that it's due to the "Positive Neutral Finder" feature? Sometimes I can shift into 2nd relatively smooth if I apply pressure to the shift lever before shifting. The other gears engage smoothly and pleasantly, so I think I generally do it right. I'm nearing the end of my break-in period and will also ask at the service center, but I'm curious about other owners of new Z900. With KQS on, shifting gears is a music to my ears :)