ElasticSearch HighLevel Rest client returns java.net.SocketTimeoutException

[ilBepi (Giuseppe Lio)]

Hello,
I am updating Elasticsearch from version 7.4 to 7.17.
My code instantiates an ElasticSearchNode, starts it, and then creates a HighLevel Rest client to make calls to that node.
The node is local to the machine, and the address to which the client points is localhost with a certain port.
When I try to make a putTemplate call with the client, I get the following exception:

java.net.SocketTimeoutException: 120,000 milliseconds timeout on connection http-outgoing-0 [ACTIVE]
        at org.elasticsearch.client.RestClient.extractAndWrapCause(RestClient.java:917) ~[elasticsearch-rest-client-7.17.6.jar:7.17.6]
        at org.elasticsearch.client.RestClient.performRequest(RestClient.java:300) ~[elasticsearch-rest-client-7.17.6.jar:7.17.6]
        at org.elasticsearch.client.RestClient.performRequest(RestClient.java:288) ~[elasticsearch-rest-client-7.17.6.jar:7.17.6]
        at org.elasticsearch.client.RestHighLevelClient.performClientRequest(RestHighLevelClient.java:2699) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
        at org.elasticsearch.client.RestHighLevelClient.internalPerformRequest(RestHighLevelClient.java:2171) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
        at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:2137) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
        at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:2105) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]
        at org.elasticsearch.client.IndicesClient.putTemplate(IndicesClient.java:1867) ~[elasticsearch-rest-high-level-client-7.17.6.jar:7.17.6]

I have already tried to add connectionRequestTimeout as someone suggested but without success:

            restClientBuilder.setRequestConfigCallback(new RestClientBuilder.RequestConfigCallback() {
                @Override
                public RequestConfig.Builder customizeRequestConfig(RequestConfig.Builder requestConfigBuilder) {
                    return requestConfigBuilder.setConnectTimeout((int) timeout)
                            .setSocketTimeout((int) timeout)
                            .setConnectionRequestTimeout((int) timeout);
                }
            }); 

I would like to point out that, with version 7.4, everything works perfectly, so it is not a matter of ports already in use, or network connections.

If anyone could give me some help, it would be really appreciated.

Thanks very much

Giuseppe