For words that only have 3 letters, there is not any 4th letter. For example with the word “include”, there isn't any far more letters Later on and so needs to be the word "insert". The word “addict” is while in the BIP39 wordlist but you might have employed “addi” https://thejillist.com/story8922073/the-basic-principles-of-bip39-passphrase-generator