cb-cmds: setting dhcp4o6-port does not work

Issued command:

{'arguments': {'parameters': [{'name': 'dhcp4o6-port', 'value': 4321}],
               'remote': {'type': 'mysql'},
               'server-tags': ['default']},
 'command': 'remote-global-parameter4-set',
 'service': ['dhcp4']}
[
  {
    "result": 0,
    "text": "DHCPv4 global parameter successfully set."
  }
]

Result of config-get after config-reload:

        ...
        "dhcp-queue-control": {
          "capacity": 500,
          "enable-queue": false,
          "queue-type": "kea-ring4"
        },
        "dhcp4o6-port": 0,
        "echo-client-id": true,
        "expired-leases-processing": {
          "flush-reclaimed-timer-wait-time": 25,
          "hold-reclaimed-time": 3600,
        ...