Shibboleth SSO failed : No valid data received

Hello everyone
I have installed an indico server (the latest version) for an international graduate school at my university. Everything is working fine using the local LDAP authentication, but i need to access the French RENATER EduGAIN shibboleth as a SP provider.
Following the documentation, I have configured both the Apache shibboleth module and the indico.
I can connect to the RENATER discovery, select my university and login with my university ID, but when I get back to indico, I received Login Failed: no valid data received , and in indico.log

 ERROR    b68002ab64ae4bcf  -       indico.auth               Authentication via shib-sso failed: No valid data received (None)

In the log file of Apache shibboleth : transaction.log I got

2023-11-19 18:01:22|Shibboleth-TRANSACTION.AuthnRequest|||urn:mace:cru.fr:federation:univ-lyon1.fr||||||urn:oasis:names:tc:SAML:2.0:bindings:HTTP-Redirect||||||
2023-11-19 18:01:47|Shibboleth-TRANSACTION.Login|2747@univ-lyon1.fr|_201ad4d23828f016c46d5f49f85e1e15|urn:mace:cru.fr:federation:univ-lyon1.fr|_56c52975e8831bfeed5757dc19510529|urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport|2023-11-19T18:01:39|eppn(1),givenName(1),mail(1),sn(1)|AAdzZWNyZXQxmjjedYmsGkBRB00p1XewbBqPZEwCvlzjqMXaek/Q7cBajAnxnTyBifRtC/Kv0XiWbMJpUQrxEOvib4IyRgbcUqQ8/p11s5lL/7x/uXDw1Er8ZLMn0voIFItWSZMBt1JWFoKcxMXN+wBYuRsXFy1gQF8jYOg6H5ypoXokSaU=|urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST||urn:oasis:names:tc:SAML:2.0:status:Success|||Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36|172.29.16.183

As the status is success, it seems that the authentication with Apache-shibboleth works.
So the problem seems to be between Apache shibboleth and indico
My indico.conf is

# LDAP et SSO (default LDAP)
AUTH_PROVIDERS = {
    'ldap': {
        'type': 'ldap',
        'title': 'Compte Lyon1 (LDAP)',
        'ldap': _ldap_config,
        'default': True
    },
    'shib-sso': {
        'type': 'shibboleth',
        'title': 'Autre établissement (eduGAIN)',
        'attrs_prefix': 'ADFS_',
        'callback_uri': '/login/shib-sso/shibboleth',
        # 'logout_uri': 'https://login.yourcompany.tld/logout'
    }
}

IDENTITY_PROVIDERS = {
    'ldap': {
        'type': 'ldap',
        'title': 'LDAP',
        'ldap': _ldap_config,
        'mapping': {
            'first_name': 'givenName',
            'last_name': 'sn',
            'email': 'mail',
            #'affiliation': 'company',
            #'phone': 'telephoneNumber'
        },
	'affiliation': 'Université Claude Bernard Lyon 1',
        'trusted_email': True,
        #'synced_fields': {'first_name', 'last_name', 'affiliation', 'phone', 'address'}
        'synced_fields': {'first_name', 'last_name'}
    },
    'shib-sso': {
        'type': 'shibboleth',
        'title': 'SSO',
        #'identifier_field': 'ADFS_LOGIN',
        'mapping': {
            #'first_name': 'ADFS_GIVENNAME',
            #'last_name': 'ADFS_SN',
            #'email': 'ADFS_MAIL',
            'first_name': 'givenName',
            'last_name': 'sn',
            'email': 'mail',
            #'affiliation': 'eduPersonScopedAffiliation',
            # 'phone': 'ADFS_PHONENUMBER'
        },
        'trusted_email': True,
        #'synced_fields': {'first_name', 'last_name'}
    }
}

Any help will be highly appreciated
Marc
PS: i have read an old discussion by mbile in the administrators section at Jan 2021, but it does not help .