I took the index with the words, transformed the number to binary, additional 3 zeros, calculated the sha256 digest, took the first Section of the hexadecimal to transform it to binary, added 3 zeros to your eight digits of your binary and got 00000010011 which interprets to 19 in decimal. https://bookmarkmargin.com/story18909372/fascination-about-invalid-bip39-phrase