I took the index with the words, converted the variety to binary, added three zeros, calculated the sha256 digest, took the 1st A part of the hexadecimal to transform it to binary, included three zeros to your 8 digits with the binary and got 00000010011 which translates to 19 in https://bookmarkchamp.com/story18928966/not-known-factual-statements-about-bip39-explained