Getting 400 error when using Jira Service Desk APi to create Attachment

I am using JSM rest api to create tickets. I use “/servicedeskapi/request/xxx/attachment” and sending the temporary file Ids and its throwing 400 error, but not always most of the request are success and some are failing and returning 400 ,
One of the failed request is given below , but when i tried the same request with same payload in POSTMAN it went through and attachments got added to the ticket.

POSTMAN request:

POST https://*****/rest/servicedeskapi/request/xxx/attachment
Header:
Authorization: Basic *******

Body:
{
“public”:true,
“temporaryAttachmentIds”:[“6f06d169-dc83-456a-ba92-5626536e2865”,“969e9d2b-0d2e-433b-abf1-8885f89524ca”]
}

Note: Im not getting 400 everytime but some time it throws 400
Is there any limit in which we can invoke these api’s?