For words that only have 3 letters, there is no 4th letter. For example with the word “insert”, there are no far more letters afterwards and thus must be the word "incorporate". The word “addict” is from the BIP39 wordlist however, you might have utilized “addi” for “addict”. To test https://bookmarkforce.com/story19561793/invalid-bip39-phrase-things-to-know-before-you-buy