I have a web service(FastAPI) deployed on AWS EC2.

In java client code, when I call the api, i got this error

org.apache.http.ConnectionClosedException: Premature end of Content-Length delimited message body (expected: 3,849,324; received: 1,834,837)

In postman, when I call this api, the response is returned but not enough like this image

Seem the server (Fast API web service) do not return all data in response body.

I already check this question, the accepted answer said that this error is belong server-side.

So what is the problem here? What can I configure to solve this problem, on the AWS or my web service or any ?

Additional information, in the API implementation, business logic is connect to the AWS S3 and download some files. I don't know if this is the problem but when I looked for solution, a lot of people said it related to AWS S3

Thank you all guys!!!