Did they do any cutting of the Quartz near where the drawers are clunking? If so then I'd guess counter grit/dust

It is not normal, but you know that already

No, the quartz wasn't cut near the drawers. It is loud enough that I hear the drawers clunking away while I am going about my normal kitchen routine or cooking. We were told the drawers in the showroom do the same thing but we stopped in today to see and it is definitely not true. We told them they are unacceptable as they are now. Not sure what they will do. Replace the slides?

Ours (which are not Blum) were silent until one slide broke (we think from the weight, although we hadn't over-stuffed that drawer). We took a video so our cabinet person could hear the awful noise it made. We were sent heavy duty replacement slides immediately (and fortunately have a handyman who could install them).

i have medallion silverline cabs and they clunk too, especially the top drawers. they have been installed since April and have always made that noise.
is it possible that it is the kind of glide? if the experts say no then mine are wonky too!

I had clunking in 2 drawers. It went away when I tightened the bracket screws.

Empty the drawers and try them empty to see if they clunk. If so, then release the latch below and remove the drawer. Check the brackets on the sides. Sometimes the screws are loose but don't look loose.

My soft close drawer is making a squeaking noise that's very loud just when the drawer is about to close, how to fix that?

WeWe’re havhaving this problem too. it soun like a gas or air release. How do we make them quiet again???