Why did my customer get overcharged for sales tax?

12 0 13

A customer recently made a purchase from us and sales tax significantly overcharged on their order. They live in Grand Canyon Village, AZ, but were charge municipal sales tax for William, AZ, a city 60 miles away. I know that Shopify's sales tax calculations are often incorrect (they really need to fix that), but to not even correctly determine which taxes to charge and selecting one over an hours drive away from the delivery location is beyond ridiculous.