Hi @Adriano Cezar Sousa Neves
Thank you for reaching Microsoft Q&A Forum and Sorry for the delay response.
If I understand correctly, the AD user's password expires but the users are able to access the office 365 resources with the expired password.
May I know these AD users are synchronized to Entra ID with Entra Connect, if yes it might be the issue with password policy is not comply with the Entra ID.
To fix this issue enable the CloudPasswordPolicyForPasswordSyncedUsersEnabled
feature, which enforces cloud password policies for users whose passwords are synchronized from on-premises Active Directory (AD) to Entra ID (Azure AD). This ensures that synchronized users comply with the Azure AD password expiration policy, even if their on-premises password has expired. By default, this feature is disabled.
Reference: CloudPasswordPolicyForPasswordSyncedUsersEnabled
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