Hey there! Nice to meet you!
The error message you provided indicates that you may have tried signing in too many times or there's possibly an issue with your app, browser, device, or network service, as stated by Microsoft: https://support.microsoft.com/account-billing/error-400-when-signing-in-7af27146-7624-4397-a374-6f8eae4367fe
Kindly perform these steps to fix the error:
- Sign in using a different sign-in method by selecting "Other ways to sign in" on account.microsoft.com
- Please make sure to update your app/devices, then try again.
- Sign in using different devices, such as phone, computer, or tablet, and using different network services
Thank you for your understanding.
Best regards,
Darhyl