No available endpoints ERROR when setting up kie-server with https url

Issue

We have enabled https in kie-server of RHPAM 7.x and we are able to access the endpoint using the browser.

However, we are facing issues when accessing kie-server using the remote API based on KieServicesClient:

    public static final String REST_SERVER="https://HOST:PORT/kie-server/services/rest/server";

            KieServicesConfiguration config;
            config = KieServicesFactory.newRestConfiguration(REST_SERVER, USER_ID, PASSWORD);
            KieServicesClient kieServicesClient = KieServicesFactory.newKieServicesClient(config); 

This results in the exception below (although using http endpoint works fine):

    org.kie.server.common.rest.NoEndpointFoundException: No available endpoints found
    at org.kie.server.client.balancer.impl.AbstractBalancerStrategy.checkEmpty(AbstractBalancerStrategy.java:27)
    at org.kie.server.client.balancer.impl.RoundRobinBalancerStrategy.next(RoundRobinBalancerStrategy.java:37)
    at org.kie.server.client.balancer.LoadBalancer.getUrl(LoadBalancer.java:52)
    at org.kie.server.client.impl.AbstractKieServicesClientImpl.invoke(AbstractKieServicesClientImpl.java:809)
    at org.kie.server.client.impl.AbstractKieServicesClientImpl.makeHttpGetRequestAndCreateServiceResponse(AbstractKieServicesClientImpl.java:177)
    at org.kie.server.client.impl.KieServicesClientImpl.getServerInfo(KieServicesClientImpl.java:157)
    at org.kie.server.client.impl.KieServicesClientImpl.getCapabilitiesFromServer(KieServicesClientImpl.java:130)
    at org.kie.server.client.impl.KieServicesClientImpl.init(KieServicesClientImpl.java:85)
    at org.kie.server.client.impl.KieServicesClientImpl.<init>(KieServicesClientImpl.java:72)
    at org.kie.server.client.KieServicesFactory.newKieServicesClient(KieServicesFactory.java:101)
    at com.eh.ewt.context.TestContext.main(TestContext.java:23)