Hostname null when sending message to MQ - ibm-mq

Question

I am trying to send a message to a MQ 9 queue.
I get this error message, and I don't understand why the hostname is null: Failed to connect to queue manager x with connection mode 'Client' and host name 'null'
Here is the source code:
JmsFactoryFactory ff = JmsFactoryFactory.getInstance(WMQConstants.WMQ_PROVIDER);
JmsConnectionFactory cf = ff.createConnectionFactory();
// Set the properties
cf.setStringProperty(WMQConstants.WMQ_HOST_NAME, HOST_NAME);
cf.setIntProperty(WMQConstants.WMQ_PORT, PORT);
cf.setStringProperty(WMQConstants.WMQ_CHANNEL, CHANNEL);
cf.setIntProperty(WMQConstants.WMQ_CONNECTION_MODE, WMQConstants.WMQ_CM_CLIENT);
cf.setStringProperty(WMQConstants.WMQ_QUEUE_MANAGER, QUEUE_MANAGER);
cf.setStringProperty(WMQConstants.WMQ_APPLICATIONNAME, "JmsPutGet (JMS)");
cf.setBooleanProperty(WMQConstants.USER_AUTHENTICATION_MQCSP, true);
//cf.setStringProperty(WMQConstants.USERID, APP_USER);
//cf.setStringProperty(WMQConstants.PASSWORD, APP_PASSWORD);
cf.setStringProperty(WMQConstants.WMQ_SSL_CIPHER_SUITE, SSL_CIPHER_SUITE);
cf.setStringProperty(WMQConstants.WMQ_SSL_PEER_NAME, SSL_PEER_NAME);
//System.setProperty("javax.net.ssl.keyStore", "path_to_jks");
//System.setProperty("javax.net.ssl.keyStorePassword", "pass");
System.setProperty("javax.net.ssl.trustStore", path_to_cacerts");
System.setProperty("javax.net.ssl.trustStorePassword", "pass");
System.setProperty("com.ibm.mq.cfg.useIBMCipherMappings", "false");
//create connection, session manually
Connection connection = cf.createConnection();
connection.start();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Destination requestQueue = session.createQueue("queue:///" + QUEUE_MANAGER + "/" + QUEUE_NAME);
MessageProducer messageProducer = session.createProducer(requestQueue);
long uniqueNumber = System.currentTimeMillis() % 1000;
TextMessage message = session.createTextMessage("Your lucky number today is " + uniqueNumber);
messageProducer.send(message);
As far as I understand it should get picked up by the WMQ_HOST_NAME which is set.
This is the full stacktrace
getLinkedException()=com.ibm.mq.MQException: JMSCMQ0001: IBM MQ call failed with compcode '2' ('MQCC_FAILED') reason '2400' ('MQRC_UNSUPPORTED_CIPHER_SUITE').
JMSWMQ0018: Failed to connect to queue manager 'T01A02K' with connection mode 'Client' and host name 'null'.
com.ibm.msg.client.jms.DetailedJMSException: JMSWMQ0018: Failed to connect to queue manager 'T01A02K' with connection mode 'Client' and host name 'null'.
Check the queue manager is started and if running in client mode, check there is a listener running. Please see the linked exception for more information.
at com.ibm.msg.client.wmq.common.internal.Reason.reasonToException(Reason.java:595)
at com.ibm.msg.client.wmq.common.internal.Reason.createException(Reason.java:215)
at com.ibm.msg.client.wmq.internal.WMQConnection.getConnectOptions(WMQConnection.java:1583)
at com.ibm.msg.client.wmq.internal.WMQConnection.<init>(WMQConnection.java:388)
at com.ibm.msg.client.wmq.factories.WMQConnectionFactory.createV7ProviderConnection(WMQConnectionFactory.java:8683)
at com.ibm.msg.client.wmq.factories.WMQConnectionFactory.createProviderConnection(WMQConnectionFactory.java:8023)
at com.ibm.msg.client.jms.admin.JmsConnectionFactoryImpl._createConnection(JmsConnectionFactoryImpl.java:322)
at com.ibm.msg.client.jms.admin.JmsConnectionFactoryImpl.createConnection(JmsConnectionFactoryImpl.java:242)
at com.ibm.mq.jms.MQConnectionFactory.createCommonConnection(MQConnectionFactory.java:6026)
at com.ibm.mq.jms.MQQueueConnectionFactory.createQueueConnection(MQQueueConnectionFactory.java:111)
at com.bmw.fisp.SimplePTPWithSSLCertificate.postMessage(SimplePTPWithSSLCertificate.java:49)
at com.bmw.fisp.SimplePTPMain.main(SimplePTPMain.java:9)
Caused by: com.ibm.mq.MQException: JMSCMQ0001: IBM MQ call failed with compcode '2' ('MQCC_FAILED') reason '2400' ('MQRC_UNSUPPORTED_CIPHER_SUITE').
at com.ibm.msg.client.wmq.common.internal.Reason.createException(Reason.java:203)
... 10 more