ZITADEL is a combination of Auth0 and Keycloak. RefreshTokens is an OAuth 2.0 feature that allows applications to retrieve new access tokens and refresh the user's session without the need for interacting with a UI. RefreshTokens were not invalidated when a user was locked or deactivated. The deactivated or locked user was able to obtain a valid access token only through a refresh token grant. When the locked or deactivated user’s session was already terminated (“logged out”) then it was not possible to create a new session. Renewal of access token through a refresh token grant is limited to the configured amount of time (RefreshTokenExpiration). As a workaround, ensure the RefreshTokenExpiration in the OIDC settings of your instance is set according to your security requirements. This issue has been patched in versions 2.17.3 and 2.16.4.