Hmm, now that you mentioned it around the time I started getting notices about the new Outlook and that I need to try it I noticed a problem copying and pasting stuff out of Thunderbird. Not sure if it's connected or just a random Thunderbird problem I just now noticed
Microsoft is pushing the new Outlook VERY hard. No matter how many times I reject it, they keep switching me over to it without my permission, so then I have to manually change back.
I have MS Office Professional -- 2016 on one computer, 2019 on another, and 2021 on a third. And I have MS Office Home and Business on my Surface tablet. All of those include the
real Outlook -- with no ads interspersed with new e-mail messages. I have two e-mail accounts set up in [the real] Outlook. I have no problem with that. But I use the Windows Calendar for the simple reason that I can set a desktop icon for it and, when I need it, it opens directly into a calendar view. No need to open Outlook and then jump from mail to calendar, and then back. It works for me, and I have no desire to change. So I wish Microsoft would take a hint and just leave me alone.