Error sending SOAP request from Delphi

The server uses certificate validation. When sending a request, after selecting the certificate I get an error

"Запрашиваемый заголовок не найден - URL:https://address - SOAPAction:GetMessage". 

Checking the generated soap request, it looks quite correct. What can lead to a similar error?

Request:

 ><s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"> <s:Header> <NS1:RequestHeader xmlns:NS1="http://dom.gosuslugi.ru/schema/integration/8.6.0.6/nsi-common-service/"> <Date>02.04.2016 19:54:22</Date> <MessageGUID>{1FF99D89-A093-4683-B8E4-AC76E8DAB58E}</MessageGUID> </NS1:RequestHeader> </s:Header> <s:Body xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <exportNsiListRequest Id="foo" xmlns="http://dom.gosuslugi.ru/schema/integration/8.5.0.4/nsi/"> <ds:Signature Id="xmldsig-0f4efe13-1ee4-42a3-b139-25ae3bb6d371" xmlns:ds="http://www.w3.org/2000/09/xmldsig#"> <ds:SignedInfo> <ds:CanonicalizationMethod Algorithm="http://www.w3.org/TR/2001/REC-xml-c14n-20010315"/> <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr34102001-gostr3411"/> <ds:Reference Id="xmldsig-0f4efe13-1ee4-42a3-b139-25ae3bb6d371-ref0" URI="#foo"> <ds:Transforms> <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/> <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/> </ds:Transforms> <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr3411"/> <ds:DigestValue>eXgrWAI4XI/2EHUUP2AhVs8ZL8cNLrqinerk1VifrXE=</ds:DigestValue> </ds:Reference> <ds:Reference Type="http://uri.etsi.org/01903#SignedProperties" URI="#xmldsig-0f4efe13-1ee4-42a3-b139-25ae3bb6d371-signedprops"> <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr3411"/> <ds:DigestValue>9qsLyxEb4yINDtg95mtcpkdA/wWfKpu/31TmngJyftI=</ds:DigestValue> </ds:Reference> </ds:SignedInfo> <ds:SignatureValue Id="xmldsig-0f4efe13-1ee4-42a3-b139-25ae3bb6d371-sigvalue">vELE7F7yTzaEBbL6G23MaDah6JpzhhG3Z6ewmDoA43qF1mgSD0R8E5tBs0QC+2Xj/sBX5C7Vuv62/bdB+h30Pw==</ds:SignatureValue> <ds:KeyInfo> <ds:X509Data> <ds:X509Certificate>value</ds:X509Certificate> </ds:X509Data> </ds:KeyInfo> <ds:Object> <xades:QualifyingProperties Target="#xmldsig-0f4efe13-1ee4-42a3-b139-25ae3bb6d371" xmlns:xades="http://uri.etsi.org/01903/v1.3.2#" xmlns:xades141="http://uri.etsi.org/01903/v1.4.1#"> <xades:SignedProperties Id="xmldsig-0f4efe13-1ee4-42a3-b139-25ae3bb6d371-signedprops"> <xades:SignedSignatureProperties> <xades:SigningTime>value</xades:SigningTime> <xades:SigningCertificate> <xades:Cert> <xades:CertDigest> <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr3411"/> <ds:DigestValue>value</ds:DigestValue> </xades:CertDigest> <xades:IssuerSerial> <ds:X509IssuerNamevalue</ds:X509IssuerName> <ds:X509SerialNumber></ds:X509SerialNumber> </xades:IssuerSerial> </xades:Cert> </xades:SigningCertificate> </xades:SignedSignatureProperties> </xades:SignedProperties> </xades:QualifyingProperties> </ds:Object> </ds:Signature> </exportNsiListRequest> </s:Body> </s:Envelope>