For words that only have 3 letters, there's no 4th letter. For example with the word “include”, there isn't any far more letters afterwards and therefore has to be the word "add". The word “addict” is within the BIP39 wordlist however, you might have used “addi” for “addict”. Standard recovery https://wiishlist.com/story19561879/considerations-to-know-about-bip39-seed-phrase-generator