Microsoft ToDo, Outlook tasks, OneNote - doesn't work (Folders)

Hi allobar. Not sure if the 'same problem' to which you refer is that cited by JennySihvonen (Oct '19), and by yourself back in 16, but I just had that problem and found a cause. In my case, pre-existing task flags had 'died' and newly created ones were going into the task folder associated with another mailbox. So the OneNote/Outlook dimension was behaving as though I had signed in to an account other than the one with which I'd actually signed in. With the help of a support agent, I went to File > Account Settings > Email and found that the wrong email account was selected as default. We corrected that, but still no joy. Then we went to File > Account Settings > Data Files and saw need of the same correction. (black tick indicating 'default' was on the wrong data file listing). This time: joy! Tasks newly created in OneNote were now appearing in the right folder of Outlook Tasks, and, joy of joys, all the pre-existing tasks had now come 'live' again. If you or anyone else with the issue has more than one mailbox running in Outlook then the File > Outlook Settings > Data Files.