I immediately noticed an unusual (to my ears) usage of the phrase "down to you" in her article: "it’s not down to you ... it's down to others.". Where I'm from

I immediately noticed an unusual (to my ears) usage of the phrase "down to you" in her article: "it’s not down to you ... it's down to others.". Where I'm from in the states, we usually say "up to you" to mean something isn't one's choice. Is this another odd difference between American and British English?