Last night at 0114 was when I could last get my gmail via Thunderbird. Nothing changed software version wise (except maybe Avast's def files) until I started troubleshooting the problem. It keeps reporting that "connection to server pop.gmail.com was reset." Outgoing mail is blocked saying authentication Oauth not supported service.
Upgrading to Avast (Free) 20.7 does not fix it.
Disabling Avast's MailShield DOES fix problem.
Have Thunderbird 78.2.1, but Manifested under version 68.x.x.
It used to be that I had to force-generate a certificate through Avast that I could import into Thunderbird, but that option doesn't exist in Avast anymore. There are three Avast Web/Mail Shield Root already in Thunderbird, valid from 2010 until 2040.
Have Windows 10 Pro, 1909.
Anyone have suggestions on what to do with this mess?