Hi @MichalP
After you provided the tenant details via private message, we checked on the backend using the tenant ID and noticed that there is another Global Administrator available in your tenant. We suggested signing in with that account, and you've now confirmed that you were able to successfully sign in.
Since there is another Global Administrator in your tenant, they can initiate MFA recovery for your other account. Please note that this action will remove all existing MFA methods, including phone numbers, Microsoft Authenticator apps, and software OATH tokens. You will be required to set up a new MFA method the next time you sign in.
For your reference: https://learn.microsoft.com/en-us/entra/identity/authentication/howto-mfa-userdevicesettings#manage-user-authentication-options
Hope this helps. Do let us know if you any further queries.
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