Need help creating component and sending post

We host two sites on a typical Windows Server 2016 shared-hosting provider. We use ASP Classic writing in javascript. We post credit card transactions to Authorize.net using the MSXML2.ServerXMLHTTP.6.0 object. It works perfectly, except that in five out of ten times (about half the time), when the MSXML2.ServerXMLHTTP.6.0 object sends the post, it times out with this error:

msxml6.dllerror '80072ee2'

The operation timed out 

We created a test post to https://www.howsmyssl.com/a/check and get the same result, so the timeout is being caused by our server trying to send the post and not authorize.net.

We have tested creating the object three different ways:

objRequest = Server.CreateObject("MSXML2.ServerXMLHTTP.6.0")

objRequest = new ActiveXObject("MSXML2.ServerXMLHTTP.6.0")

objRequest = Server.CreateObject("WinHTTP.WinHTTPRequest.5.1")

Then we set up the post and send:

objRequest.open("GET", post_url, false);
objRequest.send();

We have researched this thoroughly, but cannot find an explanation of why it may be timing out half the time (the send() line is the line that times out) and we cannot find out what the difference is between "Server.CreateObject" and "new ActiveXObject" but both work fine when it doesn't time out.

Any help with these two issues would be helpful

Thank you.