As a cashier myself, this is so true. I say no problem all the time, and no one else has a problem. You sound just as nice when you say "no problem" vs. "youre welcome" ; Agreed, I say "No problem" to people all the time.
"On board with this - only thing I'd like to also make note of is how often both jokes about white people and POC target girls more frequently then guys. Just wanted to draw attention to the inherent sexism also present around this subject.