I do not think they have a 'solution'. Installer was changed in terms of authentication and I am using same PC as year ago - last year installed TT deluxe 2019 without issues, this time TT 2020 after entering license cannot authenticate response (log says error in ssl/tls ... oauth etc). i spent hour with support on the phone, asking to turn off antivirus (no way), firewall, reboot, etc - does not work. they sent me new installer tailor for my state - with license - exactly the same error. so my 'solution' was find another PC in different network - from there with the same antivirus their new installer worked from the first time.
another thing is - they tried to do remote desktop and sent me their app - which cannot be installed - rdc installer flashes and dies...
so - call them, try options, if does not work (likely), try their fresh tailored for you installer, possibly in another PC/network
