JavaScript window.location does not set referer in the request header

I understand relying on Referer in the request header is not right. But my question is, why IE does not set Referer to the Request Header if I use window.location? Any thoughts or fixes?

This does not set Referer in the Request header:

function load1() {
   window.location = "https://" + serverURL + "/path/folder/page.aspx";
}

<a href="javascript:load1()">Link 1</a>

While this sets:

<a href="https://hardcode.server.url/path/folder/page.aspx">Link 1</a>