First-time login via SAML - will save the required fields in the database, such as name, and surname of the user. which comes from the IDP, and this happens only once on the first time login.
After some time If the IDP updates the user's surname for whatever reason - the invenio does not know the new surname of the user. because it is not trying to save/check the changes.
should find a decent solution - and keep the SP (invenio) - updated from certain changes.