Hello,
From the Start menu list, please right‑click Outlook and open App settings.
Then click Terminate, Repair, and Reset, in that order.
After completing these steps, close all applications and shut down the PC while holding the Shift key.
Turn the PC back on, and once the desktop appears, please wait for about three minutes before attempting to use Outlook.
If the issue still persists, return to the Start menu list, right‑click Outlook again, open App settings, and select Uninstall.
After uninstalling, please restart Windows.
Next, open the Microsoft Store, search for Outlook, and install “Outlook for Windows.”
Once installed, please try signing in again.