Unable to fetch shipment id for a Parent Invoice (both standard and secondary Shipments) via API

Summary:

Unable to fetch Secondary charge shipment id via Invoice Shipments API.

Using below API

https://{OTMurl}.oraclecloud.com:443/logisticsRestApi/resources/v2/{invoice_id}/shipments

Results:

Getting the Invoice id href, but shipment id href is missing

{
"hasMore": false,
"limit": 25,
"count": 0,
"offset": 0,
"items": [],
"links": [
{
"rel": "self",
"href": "https://{OTMurl}.ocs.oraclecloud.com:443/logisticsRestApi/resources/v2/invoices/{invoice_id}/shipments"
}
]
}

Content (please ensure you mask any confidential information):

Getting the Invoice id href, but shipment id href is missing

{"hasMore": false,"limit": 25,"count": 0,"offset": 0,"items": [],"links": [{"rel": "self","href": "https://{OTMurl}.ocs.oraclecloud.com:443/logisticsRestApi/resources/v2/invoices/{invoice_id}/shipments"}]}