Hello, TH13FO
Welcome to Microsoft Community.
I'm sorry to hear that you're experiencing issues with entering the two-step verification code on your PC. There could be several reasons why this is happening, and it may not necessarily be related to a virus or a mysteriously reset setting. May I know if you're entering the code in a browser? If so, have you tried other browsers, disabling browser extensions, or clearing the browser data? Please back up all your personal files first, such as Favorites, to ensure you do not lose data.
Also, have you tried typing numbers in a different application (e.g., Notepad) or computer to confirm that your keyboard is functioning properly, or restarting the CTF Loader process by opening the Task Manager, locating CTF Loader or ctfmon.exe in the Processes tab, and selecting “End Task” (This will close the process and it should restart automatically)?
It may also be worth considering creating a local user or administrator account in Windows, performing a clean boot and using System File Checker in Windows to eliminate any potential outages caused by user profiles, background programs, or corrupt system files. These basic troubleshooting measures have broad applicability and can be attempted to solve a variety of problems.
Let me know if you have any other concerns.
Best regards
Yuhao Li
Microsoft Community Technical Support