For words that only have three letters, there is not any 4th letter. One example is with the word “include”, there isn't any additional letters Later on and so need to be the word "insert". The word “addict” is within the BIP39 wordlist however you might have employed “addi” for https://yxzbookmarks.com/story19008843/little-known-facts-about-bip39-seed-phrase-list