mcssystemready() is returning inaccurate value

[root@mcs1 /]# mariadb -e "SELECT mcssystemready()"

+------------------+

| mcssystemready() |

+------------------+

|                1 |

+------------------+

[root@mcs1 /]# mariadb -e "SELECT * FROM test.t1"

+------+

| id   |

+------+

|   99 |

|   77 |

+------+

[root@mcs1 /]# mcsShutdown

{

  "timestamp": "2022-04-28 19:10:59.906225",

  "mcs1": {

    "timestamp": "2022-04-28 19:11:09.419228"

  },

  "mcs2": {

    "timestamp": "2022-04-28 19:11:12.840278"

  },

  "mcs3": {

    "timestamp": "2022-04-28 19:11:16.240289"

  }

}

[root@mcs1 /]# mariadb -e "SELECT mcssystemready()"

+------------------+

| mcssystemready() |

+------------------+

|                1 |

+------------------+

[root@mcs1 /]# mariadb -e "SELECT * FROM test.t1"

ERROR 1815 (HY000) at line 1: Internal error: DBRM is not responding. Cannot accept queries