I took the index on the words, transformed the amount to binary, included three zeros, calculated the sha256 digest, took the main Portion of the hexadecimal to convert it to binary, included 3 zeros on the eight digits from the binary and got 00000010011 which translates to 19 in decimal. https://socialmediastore.net/story19632549/invalid-bip39-phrase-things-to-know-before-you-buy