SOAP response class not assigned (nil) - delphi

Question

I am using Delphi 10.2.3 to consume a SOAP web service. My problem is web service replies are not assigned to response classes defined in wsdl generated using WSDLImp.exe.
I see that raw response XML contains all information in it as can be seen below:
HTTP/1.1 200
X-HP-CAM-COLOR: V=1;ServerAddr=5F+cgNOCZPdfvCQ4naSfjw==;GUID=1|xpjJ6o0v_kd3rKz0c1ASIUXW--xZpHqeH8lJ3S2l30SxOi2DzpzfGfLpdqdxt0lg|L2VhcnNpdi93cy9FYXJzaXZXZWJTZXJ2aWNl
Content-Type: text/xml;charset=utf-8
Transfer-Encoding: chunked
Date: Wed, 24 Oct 2018 15:54:46 GMT
Server: EARSIV
Strict-Transport-Security: max-age=157680000
Set-Cookie: cookiesession1=1BEDB4A4PX73WJCTCIRPOUP46FNNFC28;Path=/;HttpOnly
1da
<?xml version="1.0" ?><S:Envelope xmlns:S="http://schemas.xmlsoap.org/soap/envelope/"><S:Body><ns2:faturaOlusturResponse xmlns:ns2="http://service.earsiv.uut.cs.com.tr/"><return xmlns=""><resultCode>AE00067</resultCode><resultExtra></resultExtra><resultText>Web servis çağrısı "input" alanından gerekli bilgiler elde edilemedi. Eksik alanlar: null bu alan(lar)ın boş olmadığından emin olunuz!</resultText></return></ns2:faturaOlusturResponse></S:Body></S:Envelope>
0
return in faturaOlusturResponse is nil as I see while debugging. Trying to access to return.resultCode raises an access violation.
What you see is correct that there are garbage chars just before the line XML starts and right after it. I suspected that maybe the reason.
But;
1- I see Fiddler has no problem parsing this and displaying formatted XML view with all correct information.
2- I tried to use OnAfterExecute() event of THTTPRIO. I see that SOAPResponse.Size is 474 which is equal to XML line length in above raw response.
I cannot think of what maybe the problem and could not fix it. Internet searches did not help.
Any help is appreciated.
Thanks.
WSDL URL: https://earsiv.efinans.com.tr/earsiv/ws/EarsivWebService?wsdl
EDIT:
Consuming web service method is done using AFaturaOlustur() function below. There is SetSecurityHeader() procedure which requires another unit code. I did not include them all not to post a lot of code in here. Json routines are from mORMot framework. There are some constants used in some parts of the code as well. When I read file response.xml written in HTTPRIO1AfterExecute() procedure after running function, there is complete xml. It is identical to the one in raw response above:
class procedure TMyType.HTTPRIO1AfterExecute(const MethodName: string; SOAPResponse: TStream);
var
List: TStringList;
begin
List := TStringList.Create();
try
SOAPResponse.Position := 0;
List.LoadFromStream(SOAPResponse);
List.SaveToFile('response.xml');
finally
List.Free();
end;
end;
function AFaturaOlustur(const Input: TFaturaOlusturInput; const GidenBelgeFormati: TGidenBelgeFormatlari; const GidenDosya, GelenDosya: string): Boolean;
var
RIO: THTTPRIO;
WS: EarsivWebService;
Request: faturaOlustur;
Response: faturaOlusturResponse;
Json: RawUTF8;
begin
if not TFile.Exists(GidenDosya) then
begin
LastError := 'AFaturaOlustur(): GidenDosya mevcut değil!';
end;
RIO := THTTPRIO.Create(nil);
RIO.OnAfterExecute := TMyType.HTTPRIO1AfterExecute;
RIO.URL := URLEArsivFatura;
WS := (RIO as EarsivWebService);
SetSecurityHeader(WS);
Json := RecordSaveJSON(Input, TypeInfo(TFaturaOlusturInput));
Request := nil;
Response := nil;
try
Request := faturaOlustur.Create();
Request.input := string(Json);
Request.fatura := belge.Create();
case GidenBelgeFormati of
UBL: Request.fatura.belgeFormati := belgeFormatiEnum.UBL;
CSXML: Request.fatura.belgeFormati := belgeFormatiEnum.CSXML;
HTML: Request.fatura.belgeFormati := belgeFormatiEnum.HTML;
PDF: Request.fatura.belgeFormati := belgeFormatiEnum.PDF;
CUSTOM: Request.fatura.belgeFormati := belgeFormatiEnum.CUSTOM;
PDF_CUSTOM: Request.fatura.belgeFormati := belgeFormatiEnum.PDF_CUSTOM;
PDF_UBL: Request.fatura.belgeFormati := belgeFormatiEnum.PDF_UBL;
CSXML1: Request.fatura.belgeFormati := belgeFormatiEnum.CSXML1;
CSXML2: Request.fatura.belgeFormati := belgeFormatiEnum.CSXML2;
CSXML3: Request.fatura.belgeFormati := belgeFormatiEnum.CSXML3;
PDF_CSXML1: Request.fatura.belgeFormati := belgeFormatiEnum.PDF_CSXML1;
PDF_CSXML2: Request.fatura.belgeFormati := belgeFormatiEnum.PDF_CSXML2;
PDF_CSXML3: Request.fatura.belgeFormati := belgeFormatiEnum.PDF_CSXML3;
end;
Request.fatura.belgeIcerigi := ToByteDynArray(TFile.ReadAllBytes(GidenDosya));
try
Response := WS.faturaOlustur(Request);
except
on E: Exception do
begin
LastError := 'AFaturaOlustur(): ' + E.Message;
Exit(False);
end;
end;
Result := Assigned(Response.return);
if Result then Result := Response.return.resultCode = rcSuccess;
if Result then
begin
TFile.WriteAllBytes(GelenDosya, ToBytes(Response.output.belgeIcerigi));
end
else
begin
LastError := 'AFaturaOlustur(): ' + Response.return.resultText;
end;
finally
Request.Free();
Response.Free();
end;
end;