I took the index of the words, transformed the selection to binary, extra a few zeros, calculated the sha256 digest, took the primary A part of the hexadecimal to transform it to binary, included three zeros to your eight digits with the binary and received 00000010011 which translates to 19 https://sites2000.com/story8814370/the-fact-about-valid-bip39-seed-phrase-that-no-one-is-suggesting