Thunderbird Tekoha Aty

From the article "Microsoft OAuth Authentication and Thunderbird in 2024" there is a screenshot showing a OAuth2 option for the SMTP server setting with STARTTLS connection security. It does not appear for me. There are only the five options, as shown in the screenshot. How do enable the option to be available in the drop-down list or set it?

The available options are:

No Authentication Normal Password Encrypted Password Kerberos / GSSAPI NTLM

I am on Thunderbird version 115.12.1 (64-bit), Windows 11, version 23H2, build 22631.3737

New Thunderbird Version 115.0 Every time Thunderbird checks for new messages, there is a popup relating to "login to my hotmail account". There is no prompt for an actual password as it is saved in the profile settings. The popup stays on screen for 3 seconds and is very annoying. This never happened with any of the previous versions. It also happens when I click "Get Messages", and it doesn't matter which one of my many inboxes has the focus. Image attached.

I've been running Tbird on Windows for many years. About 2 weeks ago something changed, either in Tbird or at Microsoft, which stops me from sending to the Office 365 SMTP server. I can send and receive using Outlook on the Office website, but I can't send locally from Tbird. Error message screenshot herewith. I have tried every possible permutation of server settings, which currently are:

Server name: smtp.office365.com Port: 587 Security: START/TLS Authentication: OAuth2

MS support says these are correct, and they are at wits' end to understand what is going on. They asked me to ask Tbird support, so I am.

I should add that at about the same time I started getting SMTP rejections in Gmail on my Android phone, and miraculously that was corrected yesterday, without any action from me. There is something odd going on at Microsoft - does anyone know what it is? My other accounts on Tbird work fine of course.