I took the index from the words, transformed the number to binary, additional three zeros, calculated the sha256 digest, took the primary A part of the hexadecimal to convert it to binary, included three zeros to your eight digits from the binary and obtained 00000010011 which interprets to 19 in https://singnalsocial.com/story4043782/getting-my-bip39-words-to-numbers-to-work