Per Andres, the power parameters need to be specified at creation time as in example below.

I deleted gytrash entry which had the problem and recreated the node with:

$ maas root machines create architecture=amd64 subarchitecture=generic min_hwe_kernel=hwe-t mac_addresses=2c:59:e5:47:2e:84 domain=oil hostname=gytrash power_parameters_power_driver=LAN_2_0 power_parameters_power_address=192.168.224.45 power_parameters_power_user=admin power_parameters_power_pass=insecure power_type=ipmi
Success.
Machine-readable output follows:
{
    "virtualblockdevice_set": [],
    "owner_data": {},
    "architecture": "amd64/generic",
    "distro_series": "",
    "status": 1,
    "status_name": "Commissioning",
    "storage": 0.0,
    "physicalblockdevice_set": [],
    "cpu_count": 0,
    "fqdn": "gytrash.oil",
    "address_ttl": null,
    "memory": 0,
    "special_filesystems": [],
    "hostname": "gytrash",
    "interface_set": [
        {
            "children": [],
            "discovered": null,
            "enabled": true,
            "id": 1041,
            "parents": [],
            "tags": [],
            "mac_address": "2c:59:e5:47:2e:84",
            "vlan": {
                "external_dhcp": null,
                "secondary_rack": null,
                "dhcp_on": true,
                "id": 5001,
                "vid": 0,
                "mtu": 1500,
                "name": "untagged",
                "resource_uri": "/MAAS/api/2.0/vlans/5001/",
                "primary_rack": "4y3h7n",
                "fabric": "fabric-0"
            },
            "params": "",
            "effective_mtu": 1500,
            "type": "physical",
            "name": "eth0",
            "resource_uri": "/MAAS/api/2.0/nodes/4y3hxd/interfaces/1041/",
            "links": []
        }
    ],
    "status_action": "start commissioning",
    "disable_ipv4": false,
    "owner": "root",
    "node_type": 0,
    "min_hwe_kernel": "hwe-t",
    "power_type": "ipmi",
    "zone": {
        "description": "",
        "name": "default",
        "resource_uri": "/MAAS/api/2.0/zones/default/",
        "id": 1
    },
    "domain": {
        "ttl": null,
        "id": 0,
        "resource_record_count": 24,
        "name": "oil",
        "resource_uri": "/MAAS/api/2.0/domains/0/",
        "authoritative": true
    },
    "status_message": "(root)",
    "osystem": "",
    "node_type_name": "Machine",
    "hwe_kernel": "",
    "system_id": "4y3hxd",
    "ip_addresses": [],
    "tag_names": [],
    "boot_disk": null,
    "swap_size": null,
    "power_state": "unknown",
    "netboot": true,
    "resource_uri": "/MAAS/api/2.0/machines/4y3hxd/",
    "boot_interface": {
        "children": [],
        "discovered": null,
        "enabled": true,
        "id": 1041,
        "parents": [],
        "tags": [],
        "mac_address": "2c:59:e5:47:2e:84",
        "vlan": {
            "external_dhcp": null,
            "secondary_rack": null,
            "dhcp_on": true,
            "id": 5001,
            "vid": 0,
            "mtu": 1500,
            "name": "untagged",
            "resource_uri": "/MAAS/api/2.0/vlans/5001/",
            "primary_rack": "4y3h7n",
            "fabric": "fabric-0"
        },
        "params": "",
        "effective_mtu": 1500,
        "type": "physical",
        "name": "eth0",
        "resource_uri": "/MAAS/api/2.0/nodes/4y3hxd/interfaces/1041/",
        "links": []
    },
    "blockdevice_set": []
}


There were no issue with the created node.