Unable to login into RH-SSO admin console with message - Invalid username or password

Issue

• While logging into RH-SSO admin console, suddenly we have started observing "Invalid username or password." in browser and below error in logs:

^[[0m12:22:36,587 TRACE [org.keycloak.authentication.DefaultAuthenticationFlow] (default task-2) Set execution status: Execution: Browser - Conditional OTP flow, status: FAILED
...................
^[[0m^[[33m12:22:36,587 WARN  [org.keycloak.services] (default task-2) KC-SERVICES0013: Failed authentication: org.keycloak.authentication.AuthenticationFlowException
        at org.keycloak.keycloak-services@18.0.6.redhat-00001//org.keycloak.authentication.AuthenticationProcessor.authenticationAction(AuthenticationProcessor.java:996)
        at org.keycloak.keycloak-services@18.0.6.redhat-00001//org.keycloak.services.resources.LoginActionsService.processFlow(LoginActionsService.java:321)

• We are unable to login into RH-SSO admin console with below error and we are sure that the admin user credential is correct

We are sorry... Invalid username or password.