Just to follow up on my previous suggestion... I no longer had Google Chrome installed on my laptop, so I installed it (and when I saw the voluminous user agreement that I had to accept first, I remembered why I'd previously removed it).
In Google Chrome, when I right-click on the "Download Now" button, most of the time I do not get the right-click menu that lets me choose "Open in new tab." If I close the unwanted pop-up and try again, eventually I get the right-click menu.
In Microsoft Edge, when I right-click on the "Download Now" button, I get the right-click menu every time. But if I left-click on the "Download Now" button, most of the time I get an unwanted pop-up.
I guess either Chrome is programmed to respond to a right click differently than Edge, or Chrome allows some type of script to run that Edge does not.