For words that only have 3 letters, there isn't any 4th letter. For example with the word “insert”, there aren't any a lot more letters Later on and thus needs to be the word "insert". The word “addict” is inside the BIP39 wordlist however , you would have applied “addi” https://pr1bookmarks.com/story19025248/new-step-by-step-map-for-ledger-seed-phrase-bip39