I was also discussing this in a different thread, and found THE answer a few minutes ago.
The thread is
https://ttlc.intuit.com/community/taxes/discussion/re-vanguard-brokerage-update-is-available-from-va...
I can see how changing the default browser might make it work as well, since the default settings, popup, asking, etc. might allow success.
The browser, from the intuit.com site needs to be set to have network access, I guess that means the browser is allowed to communicate with the TurboTax application running on the PC, allowing data to get into TurboTax. I really wish I did not need to learn that, but ...
