I can use all features of TinkerCad when I use my FireFox browser.
I just discovered the TinkerCad application for Windows 10 (which I am using). I installed that application and can edit my designs. However when I select the option for downloading the STL file, TC ignores the request and does not respond when I click the STL button.
This download works when requested via my FireFox browser - so why does it not work for the Windows 10 application?