OpenAM ITfoxtec Saml2 invalid signature response?-CodePudding

I'm trying to integrate OpenAM Saml SSO to my .net 5 application. ITfoxtec.Saml2 is used to handle the authentication on the SP. When trying to login, a valid post samlResponse is send. But when validating the response, I get following exception.

ERROR|Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware|An unhandled exception has occurred while executing the request. ITfoxtec.Identity.Saml2.Cryptography.InvalidSignatureException: Signature is invalid.
at ITfoxtec.Identity.Saml2.Saml2Request.ValidateXmlSignature(SignatureValidation documentValidationResult)
at ITfoxtec.Identity.Saml2.Saml2Request.Read(String xml, Boolean validateXmlSignature)
at ITfoxtec.Identity.Saml2.Saml2Response.Read(String xml, Boolean validateXmlSignature)
at ITfoxtec.Identity.Saml2.Saml2AuthnResponse.Read(String xml, Boolean validateXmlSignature)
at ITfoxtec.Identity.Saml2.Saml2PostBinding.Read(HttpRequest request, Saml2Request saml2RequestResponse, String messageName, Boolean validateXmlSignature)
at ITfoxtec.Identity.Saml2.Saml2PostBinding.UnbindInternal(HttpRequest request, Saml2Request saml2RequestResponse, String messageName)
at ITfoxtec.Identity.Saml2.Saml2Binding`1.Unbind(HttpRequest request, Saml2Response saml2Response)

Confirmed that the signature Algorithm is correct (