I guess that you are using Google Chrome? I can reproduce the behaviour on Google Chrome, but it still works fine on Firefox.

Thanks tons for reporting.

After a bit of digging, it turns out that as of Jan 2021 Google Chrome silently blocks "insecure mixed content" downloads. I.e. if a https page links to a http download, then Chrome will silently block it. As our mirror network is only provided via http and our site is https; that means that our downloads are now being blocked...

The workaround is to right click the "direct link" and select "Open in new tab|window".

We'll need to devise a proper fix, but for now, I've opened an issue and added a note to the download page.

I'm as yet unclear whether the issue is limited to Chrome. I suspect Edge and other Chromium based browsers will also be affected. I am unclear whether Safari is affected, Firwfix appears to be fine.