I use this root key: xprv9s21ZrQH143K3QTDL4LXw2F7HEK3wJUD2nW2nRk4stbPy6cq3jPPqjiChkVvvNKmPGJxWUtg6LnF5kejMRNNU3TGtRBeJgk33yuGBxrMPHi
GUI generates xprv9vwS7XPSZyi1U7wisRYieCbeotAoXBJLqG8nBA6ps8ddDHxZ5abVVW29B3DYo2XD1hH6QcT4hDUMhteq5uLRvwSsFSG8KYK9zPGjYBn8XeN
on derivation path m/0/0
but lib generates something else https://github.com/bitcoinjs/bip32/blob/master/ts-src/bip32.ts
let node: BIP32Interface = bip32.fromBase58(
"xprv9s21ZrQH143K3QTDL4LXw2F7HEK3wJUD2nW2nRk4stbPy6cq3jPPqjiChkVvvNKmPGJxWUtg6LnF5kejMRNNU3TGtRBeJgk33yuGBxrMPHi"
);
let child = node.derivePath("m/0/0");
console.log(child.toBase58());
xprv9ww7sMFLzJMzur2oEQDB642fbsMS4q6JRraMVTrM9bTWBq7NDS8ZpmsKVB4YF3mZecqax1fjnsPF19xnsJNfRp4RSyexacULXMKowSACTRc
Why difference can happen?