I understand your frustration as I was in the same boat. I even tried calling Intuit support but just got disconnected after 10 min on hold. I highly doubt screen resolution has anything to do with the activation failure (but I tried all those suggestions too).
Note it was the McAfee firewall I had to turn off, not Windows Defender. The only other thing I did was to run TurboTax as Administrator as suggested by this Community. That alone did not fix my issue, but I did have that setting still on when I disabled my firewall so perhaps both are needed.
