I took the index of the words, transformed the quantity to binary, added 3 zeros, calculated the sha256 digest, took the 1st A part of the hexadecimal to convert it to binary, additional 3 zeros to your eight digits from the binary and received 00000010011 which interprets to 19 in https://myeasybookmarks.com/story4293070/examine-this-report-on-bip39-mnemonic-phrase-tool