Microsoft issued a notice saying that starting from November 1, 2021, Office2013 and Office2016 are lower than a certain version, which will cause failure to connect to O365 normally. Since our system cannot upgrade the software, my solution is to upgrade the system to 21H1 and Office to 2019 16.0.10378.20029, I think this version may be fine, but I heard from Microsoft's customer service that it needs to be upgraded to the latest version to ensure normal connection to the 365 mailbox.
Since there is no written explanation, and the content of the notice did not mention the Office2019 version.
Reminder: Update to Microsoft 365 and Outlook for Windows connectivity
Office and Microsoft 365 Apps Outlook for Windows Version
Office 2013 15.0.4970.9999 and older
Office 2016 16.0.4599.9999 and older
Microsoft 365 Apps for enterprise (formerly Office 365 ProPlus) 1705 and older
Microsoft 365 Apps for business (formerly Office 365 Business) 1705 and older