The Return Rate That's Actually a Size Problem

Size M returns at 36% across all 20 dresses in the category, versus 9-10% for every other size — invisible if you look at any single product's overall return rate, only visible once you group by size across the whole category. DRESS-21 also has a 40% return rate across all its sizes, which looks related, but its return_reason is uniformly color_mismatch — a different problem entirely.