Getting RestTemplate (Connection Reset) Despite everything is correct

Question

I'm using Spring Boot RestTemplate to call REST API.

On PROD, I'm getting below exception:

org.springframework.web.client.ResourceAccessException: I/O error on POST request for "https://<host>/v2/graphql": Connection reset; nested exception is java.net.SocketException: Connection reset
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:785)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:711)
    at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:602)

The request from client is reached to gateway and gateway also forwarded it to the server. Server has successfully processed the request, but the connection was reset in less than 5 secs.

These are the http configs for the RestTemplate:

connectionRequestTimeoutMs: 3000
connectTimeoutMs: 3000
readTimeoutMs: 3000
maxConnectionsTotal: 100
maxConnectionsPerRoute: 100

In total 2300 requests, only 8 requests are failed with connection reset error, but I want to understand why this is happening.

Any help would really be appreciated. Thanks in advance!