12157 error on HttpSendRequest (Google Distancematrix) - api

Question

I'm using google distancematrix to calculate travel expenses for emplyees. This all worked fine a while ago, and for several clients running it on location also.
Now I'm researching a bug (that really has nothing to do with this API), and when I make the API call from my debugging environment, I get:
"HttpSendRequest Error 12157: an error occurred in the secure channel support"
When I make the same request from a browser, it all works fine and I get the XML-file I'm requesting.
This is strictly local issue; at the client site the distances are calculated just fine.
Here's the code I use:
function Https_Get(const ServerName,Resource : string;Var Response:AnsiString): Integer;
const
BufferSize=1024*64;
var
hInet : HINTERNET;
hConnect : HINTERNET;
hRequest : HINTERNET;
ErrorCode : Integer;
lpvBuffer : PAnsiChar;
lpdwBufferLength: DWORD;
lpdwReserved : DWORD;
dwBytesRead : DWORD;
lpdwNumberOfBytesAvailable: DWORD;
begin
Result :=0;
Response:='';
hConnect := InternetConnect(hInet, PChar(ServerName), INTERNET_DEFAULT_HTTPS_PORT, nil, nil, INTERNET_SERVICE_HTTP, 0, 0);
if hConnect=nil then
begin
ErrorCode:=GetLastError;
raise Exception.Create(Format('InternetConnect Error %d Description %s',[ErrorCode,GetWinInetError(ErrorCode)]));
end;
try
//make the request
hRequest := HttpOpenRequest(hConnect, 'GET', PChar(Resource), HTTP_VERSION, '', nil, INTERNET_FLAG_SECURE, 0);
if hRequest=nil then
begin
ErrorCode:=GetLastError;
raise Exception.Create(Format('HttpOpenRequest Error %d Description %s',[ErrorCode,GetWinInetError(ErrorCode)]));
end;
try
//send the GET request
if not HttpSendRequest(hRequest, nil, 0, nil, 0) then
begin
ErrorCode:=GetLastError;
raise Exception.Create(Format('HttpSendRequest Error %d Description %s',[ErrorCode,GetWinInetError(ErrorCode)]));
end;
Coded elsewhere:
sServer = 'maps.googleapis.com';
sParams = '/maps/api/distancematrix/xml?origins=%s+NL&destinations=%s+NL&sensor=false';
...
ResponseCode:=Https_Get(sServer,Format(sParams,[PostcodeVan, PostcodeNaar]), Response);
PostcodeVan and PostcodeNaar are the two ZIP codes and properly filled. Code cancels at the HttpSendRequest statement.
Anyone got any ideas? Especially the fact that it the (server+resource) link in a browser works fine dazzles me!
Thanks in advance!