I'm absolutely sure it's not user error, since the recovery phrase was present in two different destinations: backed up inside a file on S3, and printed over a bit of paper. This information explains BIP39, the standard that defines how seed phrases are made, and summarizes how BIP32 and BIP44 https://optimusbookmarks.com/story18761349/ledger-seed-phrase-bip39-no-further-a-mystery