Can't Set maintenance on master

why on maxscale version 6.4.1 can't set maintenance on the master database.

Error: Server at http://172.17.71.33:8989 responded with 403 Forbidden to `PUT servers/dbsf7_v38_71_81/set?state=maintenance`

{

    "errors": [

        {

            "detail": "The server is master, so it cannot be set in maintenance or draining mode. First perform a switchover and then retry the operation."

        }

    ]

}

because in my case master DB some time have an issue on the VM side
so I need downtime and set maintenance on the master for make sure no transaction is coming to master
before we switch over manually.

because based on my experience if the master has issue on VM and we switchover using the command switchover on maxctrl is failed because VM is not responsif

is there way to set maintenance for master ?