The "weekly download dropdown menu" shown on the right in attached picture. This menu appears when clicking on the "Downloads" button and hovering over the "weekly download" button. When going down with the mouse to select a download, it disappears.
The LTS release button works. The weekly release button works in Firefox but not in Google Chrome.
This might also be fixed by patch from issue https://issues.jenkins-ci.org/browse/WEBSITE-145