Mail, Verizon, AOL, and removed account - GRRRR

I know I can't be the only one to have this issue. We have a POP verizon.net email address that was ported to AOL a few years ago. It's worked fine until I recently got an email from Verizon saying we had to take extra steps to work with their new secure servers.

Using the information AOL published here: https://help.aol.com/articles/allow-apps-that-use-less-secure-sign-in#others I followed the link to instructions for Apple Mail here: "Remove your AOL account and re-add it to Apple Mail on Mac." https://support.apple.com/guide/mail/set-up-mail-with-your-email-accounts-mail35803/11.0/mac/10.13

About 3 days ago, I removed the old functioning Verizon/AOL account, and tried to add a new one, as directed. It refused to authenticate. I went through AOL's online information and generated a one-time password as instructed here: "Learn how to generate third-party app passwords." https://help.aol.com/articles/Create-and-manage-app-password

Mail still refuses to authenticate. I spent an hour on the phone with AOL customer support and the agent went through all the same steps multiple times, with no success. They finally said that I would have to subscribe to AOL so that he could refer me to a higher level support team.

Well, guess what, I'm going to be pretty berking bitter about having to pay money to AOL to fix something *they* broke.

I had no problem with the Mail app on my iPhone. Likewise, I still have web access.

However, the Mail app either immediately fails to authenticate, or just spins endlessly. Is there a solution anyone can offer?

As a corollary to the above, I tried to restore my removed email account via Time Machine, with no luck. Can anyone tell me specifically which files I need to restore to bring back the removed mail account?

Thanks in advance for any help.