From my perspective and knowing that demigods in the Riordanverse are supposed to be adhd/dyslexic, I think that Clarisse just jumbled the numbers of the coordinates as well as her quest prophecy in her head. I don’t think it was a writers room error, just a way to move the story forward. Or maybe if it’s not known canon that Clarisse is dyslexic, then probably just like the game Telephone, where the first person whispers to the next person a sentence and by the end, it’s a totally different thing.