For words that only have 3 letters, there isn't a 4th letter. One example is with the word “insert”, there aren't any additional letters Later on and thus need to be the word "increase". The word “addict” is while in the BIP39 wordlist but you might have used “addi” for https://other-space.uncrn.co/blog/bip39-word-list-explained-your-necessary-resource-for-creating-secure-wallets-in-the-copyright-room/