i have a loggin problem office 365

Your password change has not completed the MFA step. If the sign-in screen asks for an Authenticator verification code, a message may not be sent: open Authenticator, select the matching work account and enter its displayed code, if available. Codes are generated locally; push approvals work differently.

If that account is missing, requires registration, or no usable method appears under Sign in another way, an unregistered phone number cannot automatically serve as a fallback. Contact your organization's IT administrator. An administrator can review Entra ID > Users > your account > Authentication methods and arrange MFA re-registration after verifying your identity. Re-registration removes existing Authenticator, phone and software-OATH registrations, so coordinate it rather than deleting entries yourself.

If you are the only administrator and cannot enter the admin center, use Microsoft's Microsoft 365 business phone-support route and explain the tenant lockout. Partner-purchased subscriptions should go through the partner's support channel.