New gmail account? See Thunderbird and Gmail

The reply refers to gmail accounts established in late 2014. My account that is not accepted by T-bird has existed since Mar 2008.

That reply actually refers to ALL gmail accounts. Admittedly the details on new accounts comes first.

OK, that may explain why the old account was not accepted. But when it was not, I set up a new gmail account and that was accepted and is functioning under T-bird. SW has its idiosyncrasies but this does seem very strange to me. The old account is my wife's and its hard to explain why her existing account is rejected and my new account is working. Thanks for your replies and the chance to discuss the topic.