Can not parse request

import oci

config = oci.config.from_file()
compute_client = oci.core.ComputeClient(config)

compartment_id = "ocid1.compartment.oc1..xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"

launch_details = oci.core.models.LaunchInstanceDetails(
    availability_domain="EU-FRANKFURT-1-AD-3",
    compartment_id=compartment_id,
    shape="VM.Standard.A1.Flex",
    display_name="Server",
    source_details=oci.core.models.InstanceSourceViaImageDetails(
        source_type="image",
        image_id="ocid1.image.oc1.eu-frankfurt-1.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    ),
    create_vnic_details=oci.core.models.CreateVnicDetails(
        subnet_id="ocid1.subnet.oc1.eu-frankfurt-1.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
        assign_public_ip=True,
        assign_private_dns_record=True
    ),
    shape_config=oci.core.models.LaunchInstanceShapeConfigDetails(
        memory_in_gbs=24,
        ocpus=4
    ),
    metadata={
        "ssh_authorized_keys": open(r"/path/to/ssh-key.pub").read().strip()
    },
    agent_config=oci.core.models.LaunchInstanceAgentConfigDetails(
        is_management_disabled=False,
        is_monitoring_disabled=False,
        plugins_config=[
            {"name": "Vulnerability Scanning", "desired_state": "DISABLED"},
            {"name": "Management Agent", "desired_state": "DISABLED"},
            {"name": "Custom Logs Monitoring", "desired_state": "ENABLED"},
            {"name": "Compute RDMA GPU Monitoring", "desired_state": "DISABLED"},
            {"name": "Compute Instance Monitoring", "desired_state": "ENABLED"},
            {"name": "Compute HPC RDMA Auto-Configuration", "desired_state": "DISABLED"},
            {"name": "Compute HPC RDMA Authentication", "desired_state": "DISABLED"},
            {"name": "Cloud Guard Workload Protection", "desired_state": "ENABLED"},
            {"name": "Block Volume Management", "desired_state": "DISABLED"},
            {"name": "Bastion", "desired_state": "DISABLED"}
        ]
    ),
    instance_options=oci.core.models.InstanceOptions(
        are_legacy_imds_endpoints_disabled=False
    ),
    availability_config=oci.core.models.LaunchInstanceAvailabilityConfigDetails(
        recovery_action="RESTORE_INSTANCE"
    )
)

response = compute_client.launch_instance(launch_details)
print("Launch initiated. Instance ID:", response.data.id)

oci.wait_until(
    compute_client,
    compute_client.get_instance(response.data.id),
    'lifecycle_state',
    'RUNNING',
    max_wait_seconds=600
)
print("Instance is now RUNNING")
input()

oci.exceptions.ServiceError: {
    'target_service': 'compute',
    'status': 400,
    'code': 'CannotParseRequest',
    'opc-request-id': 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
    'message': 'Incorrectly formatted request. Please refer to our documentation for help.',
    'operation_name': 'launch_instance',
    'timestamp': '2025-08-13T15:29:34.585459+00:00',
    'client_version': 'Oracle-PythonSDK/2.157.1',
    'request_endpoint': 'POST https://iaas.eu-frankfurt-1.oraclecloud.com/20160918/instances',
    'logging_tips': 'Refer to https://docs.oracle.com/en-us/iaas/tools/python/latest/logging.html for ways to log request/response details.',
    'troubleshooting_tips': 'See https://docs.oracle.com/iaas/Content/API/References/apierrors.htm#apierrors_400__400_cannotparserequest and https://docs.oracle.com/iaas/api/#/en/iaas/20160918/Instance/LaunchInstance for more info.'
}

Start with the reproduced ComputeClient.launch_instance call and the LaunchInstanceDetails model construction, then enable SDK request logging and compare the serialized request with the linked OCI LaunchInstance API documentation. Narrow the payload to identify which field causes CannotParseRequest; done means the example launches successfully without the 400 error.