cli create node pool fails with status 500 internal error

creating a new node-pool to an existing cluster in my compartment fails. command is:

oci ce node-pool create --cluster-id $cluster_id --compartment-id $compartment_id --name "pool2" --node-shape "BM.GPU2.2" --size 0 --placement-configs '{ "availabilityDomain": "TeyJ:US-ASHBURN-AD-1", "capacityReservationId": null, "faultDomains": null, "preemptibleNodeConfig": null, "subnetId": "oke-nodesubnet-quick-cluster2-03520b506-regional" } '

oci.exceptions.TransientServiceError: {'target_service': 'container_engine', 'status': 500, 'code': 'InternalError', 'opc-request-id': 'F440E2087FCD428284E9618820099476/D15811A968B35856E00E952A69B42670/87881BD8FD6F0AD77026E5321FDF1B79', 'message': 'Internal Server Error', 'operation_name': 'create_node_pool', 'timestamp': '2023-09-12T11:57:36.092626+00:00', 'client_version': 'Oracle-PythonSDK/2.104.2', 'request_endpoint': 'POST https://containerengine.us-ashburn-1.oci.oraclecloud.com/20180222/nodePools', 'logging_tips': 'To get more info on the failing request, refer to https://docs.oracle.com/en-us/iaas/tools/python/latest/logging.html for ways to log the request/response details.', 'troubleshooting_tips': "See https://docs.oracle.com/iaas/Content/API/References/apierrors.htm#apierrors_500__500_internalerror for more information about resolving this error. Also see https://docs.oracle.com/iaas/api/#/en/containerengine/20180222/NodePool/CreateNodePool for details on this operation's requirements. If you are unable to resolve this container_engine issue, please contact Oracle support and provide them this full error message."}

Start by reproducing the oci ce node-pool create command with the supplied placement configuration and inspect the create_node_pool request and logging output. Use the reported request ID, endpoint, SDK version, and 500 response to determine whether the failure originates in the CLI request or the Container Engine service. Done means the failure is reproducible and its cause or required remediation is established.