Since Feb 24, 2020, my Office365 complaints that I need to sign in again. I tried a few times, password successfully authenticated. No error message pop up and Office still asks to sign in. Under the Account menu, there is still the Account Error: There are problems with your account, To fix them, please sign in again. I am admin of my PC and also Office365 admin. I first tried to remove my PC from my Office365 account. Also I tried to uninstall Office 365 and reinstall. I rebooted PC, and found out the Shared Experience is complaining about a Microsoft account error. I found out that the Microsoft account associated to my email address and my Office365 account (that has the same email address) may be treated separately. I sign-in to Account Microsoft account, I can see my PC under it. So I also removed the PC from there to. So now I am stuck with a non activated Office365 installation that will expire in 5 days. No error messages in Event viewer, and the company's firewall is not blocking the activation process. My account is fine as I can log on to www.office.com and Office365 admin center. I do not know where to go from here. My Windows version is the latest 1909 18363.657. Anybody who has the same issue, please shout out loud.
Update: I can activate Office365 with another PC. I am uninstalling the latest Windows update KB4532693 that brought my PC to 18363.657
