Hello,
Based on the details you shared, it is very likely that your Microsoft account has been compromised, especially since new security information was recently added without your action.
Please try recovering your Microsoft account using the official recovery form:
You can submit the form once every 24 hours.
Microsoft will review the information you provide and usually responds within 24 hours.
This is the only way to regain access to your Microsoft account and check the BitLocker recovery key page.