Correct. 5.5.4 is the latest version of Tor Browser.
So you tried Tor Browser Downloader on 2 clean installs of VirtualBox Whonix-12 Workstation on 2 separate machines and both failed with progress bar approx 50%? (and wget works properly). That’s strange.
If you took a VB snapshot prior to manually installing Tor Browser, could you restore that snapshot and try running update-torbrowser in Konsole? Will provide more info about what’s going on…