X has announced the invalidation of Passkey and Yubikey bindings previously linked to https://t.co/gY8hHoYY8E, advising users to rebind their credentials at https://t.co/Po5KZqr2mb. This move highlights the challenges associated with domain-bound authentication methods like Passkey and Yubikey, where any change in the domain, including subdomains, renders previous authentications invalid.