For words that have only three letters, there is not any 4th letter. For instance with the word “increase”, there isn't any additional letters afterwards and thus needs to be the word "include". The word “addict” is during the BIP39 wordlist but you might have utilized “addi” for “addict”. A https://bookmarkcork.com/story19382671/how-much-you-need-to-expect-you-ll-pay-for-a-good-valid-bip39-seed-phrase