For words that only have three letters, there's no 4th letter. For instance with the word “increase”, there aren't any a lot more letters afterwards and therefore should be the word "insert". The word “addict” is within the BIP39 wordlist but you might have applied “addi” for “addict”. Art is https://bookmarksden.com/story19764835/how-much-you-need-to-expect-you-ll-pay-for-a-good-bip39-seed-phrase-mnemonics-generator