For words that only have 3 letters, there isn't a 4th letter. Such as with the word “add”, there isn't any a lot more letters afterwards and so need to be the word "include". The word “addict” is from the BIP39 wordlist however you might have used “addi” for “addict”. https://sitesrow.com/story8629146/how-much-you-need-to-expect-you-ll-pay-for-a-good-valid-bip39-seed-phrase