PoolingHttpClientConnectionManager not re-using existing Idle connection

I am using Apache PoolingHttpClientConnectionManager to create a pool of conenctions. However I am seeing in the logs that the existing Idle connection is not used and rather it creates a new connection. Below is the code

PoolingHttpClientConnectionManager connManager = connManager = new PoolingHttpClientConnectionManager();
connManager.setMaxTotal(4);
    connManager.setDefaultMaxPerRoute(4);

//Creating CloseableHttpClient with a default keep alive of 2 minutes
    CloseableHttpClient  client = HttpClients.custom()
            .setConnectionManager(connManager)
            .setKeepAliveStrategy(new KeepAliveStrategy(keepAlive))
            .build();


//Sending 1st request
String xml="<xml data>";
HttpPost post = new HttpPost("<URL>");
    HttpEntity entity = new ByteArrayEntity(xml.getBytes("UTF-8"));
    post.setEntity(entity);
    HttpResponse  response =client.execute(post);
    String result = EntityUtils.toString(response.getEntity());
    EntityUtils.consume(response.getEntity());

After the response is received the PoolStats says that Total Number of available Connection is 1 .

Now I again Fire the same request after 5 seconds and upon getting the response the PoolStats states that the Total Number of available Connection is 2

The below code is for PoolStats

 PoolStats stats = connManager.getTotalStats();
    System.out.println("Total Connections Available : "+stats.getAvailable());

My Question here is Since after the First Request-response there was already a Connection in the pool so why did it create one more connection. Why it did not use the existing conenction?