I took the index of your words, transformed the variety to binary, extra three zeros, calculated the sha256 digest, took the 1st part of the hexadecimal to convert it to binary, added a few zeros for the 8 digits in the binary and received 00000010011 which translates to 19 in https://mysocialquiz.com/story4334893/5-essential-elements-for-bip39-explained