Remove member server from DAG show error

Hello

         When I remove member server from DAG then it show error

There was a problem changing the quorum model for database availability group DAG01. Error: An error occurred while attempting a cluster operation. Error: Cluster API failed: "ClusterResourceControl(controlcode=CLUSCTL_RESOURCE_SET_PRIVATE_PROPERTIES) failed with 0x533. Error: This user can't sign in because this account is currently disabled"

        I have check then see CNO account DAG01 in Active directory Disabled after I enable and remove member server again then it successful ,

        I don't why must enable then it ok

Thanks