For words that have only three letters, there is no 4th letter. Such as with the word “insert”, there isn't any far more letters Later on and thus should be the word "increase". The word “addict” is from the BIP39 wordlist however you might have applied “addi” for “addict”. An https://reallivesocial.com/story4411186/how-much-you-need-to-expect-you-ll-pay-for-a-good-valid-bip39-seed-phrase