Thanks for your fast response, the logs where helpfull,
I got the following signature failure :
ERROR [org.opensaml.security.x509.impl.BasicX509CredentialNameEvaluator:301] - Credential failed name check: [subject name]
2024-05-16 12:23:35,454 - DEBUG [org.opensaml.saml.common.binding.security.impl.SAMLProtocolMessageXMLSignatureSecurityHandler:142] - Message Handler: Validation of protocol message signature failed for context issuer my issuer', message type: {urn:oasis:names:tc:SAML:2.0:protocol}AuthnRequest
2024-05-16 12:23:35,455 - WARN [net.shibboleth.idp.profile.impl.WebFlowMessageHandlerAdaptor:202] - Profile Action WebFlowMessageHandlerAdaptor: Exception handling message
org.opensaml.messaging.handler.MessageHandlerException: Validation of protocol message signature failed
at org.opensaml.saml.common.binding.security.impl.SAMLProtocolMessageXMLSignatureSecurityHandler.doEvaluate(SAMLProtocolMessageXMLSignatureSecurityHandler.java:145)
2024-05-16 12:23:35,457 - WARN [org.opensaml.profile.action.impl.LogEvent:105] - A non-proceed event occurred while processing the request: MessageAuthenticationError
2024-05-16 12:23:35,457 - DEBUG [org.opensaml.saml.common.profile.logic.DefaultLocalErrorPredicate:154] - No SAMLBindingContext or binding URI available, error must be handled locally
Shall I create a new Trust Relation ? or maybe to create metada.xml ( is it applicable from gluu admin ?)