[BUG] [SP-API] [Issue] Vendor Shipments API v1 does not work in the sandbox

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[x] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Other... Please describe:

When using the Vendor Shipments API v1 reference (https://developer-docs.amazon.com/sp-api/docs/vendor-shipments-api-v1-reference), we encountered some issues. The GetShipmentDetails, SubmitShipments, and GetShipmentLabels endpoints not work in the sandbox environment. These endpoints were added two months ago. We want to follow up these updates. I guess, we are met with some bugs.

Vendor Shipments API v1

Current Behavior

When using GetShipmentDetails and GetShipmentLabels endpoints with same sandbox request parameters "vendorShipmentIdentifier=12345678", I get result: {"code":"InvalidInput","message":"Could not match input arguments"}. I don't know what's worry with that.
In swagger model for SubmitShipments, we found the value of packedQuantity.unitOfMeasure in x-amazon-spds-sandbox-behaviors is "Each", but the enum should be "Eaches".
In swagger model for SubmitShipments, we found some date-time value using LocalDateTime format "yyyy-MM-ddThh:mm:ss.sss". But the date-time class of my java model generated by swagger-codegen-cli is OffsetDateTime. It cannot parse "yyyy-MM-ddThh:mm:ss.sss" directly. I know I could have added a “z” after the date-time as OffsetDateTime, but I don't know if that would have affected the sandbox result.

Context/Screenshots

swagger model for GetShipmentDetails and GetShipmentLabels in Vendor Shipments API v1:

"x-amazon-spds-sandbox-behaviors": [
    {
        "request": {
            "parameters": {
                "vendorShipmentIdentifier": {
                    "value": "12345678"
                }
            }
        }
    }
]

swagger model for SubmitShipments in Vendor Shipments API v1:

"x-amazon-spds-sandbox-behaviors": [
    {
        "request": {
            "parameters": {
                "body": {
                    "value": {
                        "shipments": [
                            {
                                "vendorShipmentIdentifier": "00050003",
                                "buyerReferenceNumber": "1234567",
                                "transactionType": "New",
                                "transactionDate": "2019-08-07T19:56:45.632",           <---- here
                                "shipmentFreightTerm": "Collect",
                                "sellingParty": {
                                    "partyId": "PQRSS"
                                },
                                "shipFromParty": {
                                    "address": {
                                        "name": "ABC electronics warehouse",
                                        "addressLine1": "DEF 1st street",
                                        "city": "Lisses",
                                        "stateOrRegion": "abcland",
                                        "postalCode": "91090",
                                        "countryCode": "DE"
                                    },
                                    "partyId": "999US"
                                },
                                "shipToParty": {
                                    "partyId": "ABCDF"
                                },
                                "shipmentMeasurements": {
                                    "totalCartonCount": 30,
                                    "totalPalletStackable": 30,
                                    "totalPalletNonStackable": 30,
                                    "shipmentWeight": {
                                        "unitOfMeasure": "Kg",
                                        "value": "120.45"
                                    },
                                    "shipmentVolume": {
                                        "unitOfMeasure": "CuFt",
                                        "value": "2.4"
                                    }
                                },
                                "collectFreightPickupDetails": {
                                    "requestedPickUp": "2019-08-07T19:56:45.632"           <---- here
                                },
                                "purchaseOrders": [
                                    {
                                        "purchaseOrderNumber": "1BBBAAAA",
                                        "items": [
                                            {
                                                "itemSequenceNumber": "001",
                                                "vendorProductIdentifier": "9782700001659",
                                                "buyerProductIdentifier": "9782700001610",
                                                "shippedQuantity": {
                                                    "amount": 100,
                                                    "unitOfMeasure": "Eaches",
                                                    "unitSize": 1
                                                },
                                                "maximumRetailPrice": {
                                                    "currencyCode": "USD",
                                                    "amount": "90.80"
                                                }
                                            }
                                        ]
                                    }
                                ],
                                "importDetails": {
                                    "methodOfPayment": "PaidByBuyer",
                                    "sealNumber": "0010101",
                                    "route": {
                                        "stops": [
                                            {
                                                "functionCode": "PortOfDischarge",
                                                "locationIdentification": {
                                                    "type": "string",
                                                    "locationCode": "string",
                                                    "countryCode": "US"
                                                },
                                                "arrivalTime": "2021-07-12T22:22:25.038Z",
                                                "departureTime": "2021-07-12T22:22:25.038Z"
                                            }
                                        ]
                                    },
                                    "importContainers": "string",
                                    "billableWeight": {
                                        "unitOfMeasure": "G",
                                        "value": "string"
                                    },
                                    "estimatedShipByDate": "2021-07-12T22:22:25.038Z"
                                },
                                "containers": [
                                    {
                                        "containerType": "carton",
                                        "containerSequenceNumber": "001",
                                        "containerIdentifiers": [
                                            {
                                                "containerIdentificationType": "SSCC",
                                                "containerIdentificationNumber": "4251245123534"
                                            }
                                        ],
                                        "trackingNumber": "1Z69663R0347795889",
                                        "dimensions": {
                                            "length": "12",
                                            "width": "12",
                                            "height": "12",
                                            "unitOfMeasure": "IN"
                                        },
                                        "weight": {
                                            "unitOfMeasure": "KG",
                                            "value": "10"
                                        },
                                        "packedItems": [
                                            {
                                                "itemSequenceNumber": "001",
                                                "buyerProductIdentifier": "B07DFVDRAA",
                                                "vendorProductIdentifier": "12312412421",
                                                "packedQuantity": {
                                                    "amount": 1,
                                                    "unitOfMeasure": "Each"                            <---- here
                                                },
                                                "itemDetails": {
                                                    "purchaseOrderNumber": "MBvnLr0fw",
                                                    "lotNumber": "10101010",
                                                    "expiry": {
                                                        "manufacturerDate": "2021-07-12T22:22:25.038Z",
                                                        "expiryDate": "2021-07-12T22:22:25.038Z",
                                                        "expiryAfterDuration": {
                                                            "durationUnit": "Days",
                                                            "durationValue": 0
                                                        }
                                                    }
                                                }
                                            }
                                        ]
                                    },
                                    {
                                        "containerType": "pallet",
                                        "containerSequenceNumber": "002",
                                        "containerIdentifiers": [
                                            {
                                                "containerIdentificationType": "SSCC",
                                                "containerIdentificationNumber": "ATR123213216"
                                            }
                                        ],
                                        "trackingNumber": "TRACK12345",
                                        "dimensions": {
                                            "length": "12",
                                            "width": "12",
                                            "height": "12",
                                            "unitOfMeasure": "IN"
                                        },
                                        "weight": {
                                            "unitOfMeasure": "KG",
                                            "value": "10"
                                        },
                                        "tier": 2,
                                        "block": 2,
                                        "innerContainersDetails": {
                                            "containerCount": 10,
                                            "containerSequenceNumbers": [
                                                {
                                                    "containerSequenceNumber": "002"
                                                },
                                                {
                                                    "containerSequenceNumber": "003"
                                                }
                                            ]
                                        },
                                        "packedItems": [
                                            {
                                                "itemSequenceNumber": "001",
                                                "buyerProductIdentifier": "B07DFVDRAA",
                                                "vendorProductIdentifier": "12312412421",
                                                "packedQuantity": {
                                                    "amount": 1,
                                                    "unitOfMeasure": "Each"                                 <---- here
                                                },
                                                "itemDetails": {
                                                    "purchaseOrderNumber": "MBvnLr0fw",
                                                    "lotNumber": "101001",
                                                    "expiry": {
                                                        "manufacturerDate": "2021-07-12T22:22:25.038Z",
                                                        "expiryDate": "2021-07-12T22:22:25.038Z",
                                                        "expiryAfterDuration": {
                                                            "durationUnit": "Days",
                                                            "durationValue": 0
                                                        }
                                                    }
                                                }
                                            }
                                        ]
                                    }
                                ],
                                "transportationDetails": {
                                    "shipMode": "LessThanTruckLoad",
                                    "transportationMode": "Road",
                                    "shippedDate": "2019-08-07T19:56:45.632",
                                    "estimatedDeliveryDate": "2019-08-07T19:56:45.632",           <---- here
                                    "shipmentDeliveryDate": "2019-08-07T19:56:45.632",           <---- here
                                    "carrierDetails": {
                                        "name": "UPS",
                                        "phone": "1234567890",
                                        "email": "abc@xyz.com",
                                        "code": "string",
                                        "shipmentReferenceNumber": "TRACK123123"
                                    },
                                    "billOfLadingNumber": "1234567890"
                                }
                            }
                        ]
                    }
                }
            }
        }
    }
]

My Environment

server: Linux version 4.14.268-205.500.amzn2.x86_64 JVM: java 1.8.0_202 swagger-codegen (maven-plugin):

<groupId>io.swagger</groupId>
<artifactId>swagger-codegen-maven-plugin</artifactId>
<version>2.4.29</version>

amzn / selling-partner-api-models