Maybe it’s that you’re asking for a style that’s “unfashionable” or atypical for someone with your look so the hairdresser is second-guessing you know what you’re asking for. I bet a lot of the time they try instructions as vague as “make it shorter and look good”. They’ll err on the side of leaving it s bit long knowing they can always take a bit more off and sneak up to the desired length when it’s beyond what the normal style is.

Just get it to the length you want, then ask the hairdresser what it’s called/how to describe it and take a couple of pictures as well and you should be set for next time.