Cannot receive or send messages since recently

I have two e-mail addresses set up for Thunderbird, update 68.2.1 64-bit, on Mac; one for hotmail and one for gmail. Since November 06, my ability to both receive and send messages through my hotmail-address was lost. Prior to finding out I had already received multiple mails during the same day, as well as sent a couple of mails the day before, through Thunderbird. When I click on the "Get Messages"-button (Authetication method set to "Password form fill in the background") I get a prompt saying "Could not detect login form" at the bottom of the window. If I, instead, have the account server settings > Security Settings, Authentication method: "Open login web page" set up and restart Thunderbird, the Outlook login-page pops up in another tab shortly and it seems to log me in as intended before closing the tab - although, this is a very quick process, which makes it hard to discern if something seems off. After this, I will instead get the prompt "Login expired. Please log in to your account and try again." I am able to log in on this mail through both Outlook and Gmail, where I can still receive and send messages. The gmail-address, however, works just fine. I have the add-on Owl for Exchange installed and the license has not expired. How do I solve my problem?