[SOLVED] IBM MQ doesn't run as mqm on Openshift 4

Hi guys.
I've an IBM MQ image deployed on Openshift 4 and for some reason, the processes don't use the user mqm but the one randomly generated by Openshift itself.

As a result, I've a Java application that tries to connect to the queues and it fails because the authentication fails since it uses mqm as user.

The same exact image running on Openshift 3 behaves as expected. For more details:
Custom image:

FROM ibmcom/mq
ENV HOME /root
COPY config.mqsc /etc/mqm/

and, in the config.mqsc:

DEFINE CHANNEL(PASSWORD.SVRCONN) CHLTYPE(SVRCONN)
SET CHLAUTH(PASSWORD.SVRCONN) TYPE(BLOCKUSER) USERLIST('nobody') DESCR('Allow privileged users on this channel')
SET CHLAUTH('*') TYPE(ADDRESSMAP) ADDRESS('*') USERSRC(NOACCESS) DESCR('BackStop rule')
SET CHLAUTH(PASSWORD.SVRCONN) TYPE(ADDRESSMAP) ADDRESS('*') USERSRC(CHANNEL) CHCKCLNT(REQUIRED)
ALTER AUTHINFO(SYSTEM.DEFAULT.AUTHINFO.IDPWOS) AUTHTYPE(IDPWOS) ADOPTCTX(YES)
REFRESH SECURITY TYPE(CONNAUTH)

DEFINE QLOCAL(MYQUEUE.IN ) DEFPSIST(YES) MAXDEPTH(500000)
DEFINE QLOCAL(MYQUEUE.OUT ) DEFPSIST(YES) MAXDEPTH(500000)

DEFINE QLOCAL(CS.ERROR) DEFPSIST(YES) MAXDEPTH(500000)

ALTER QMGR CHLAUTH(DISABLED) CONNAUTH(' ')
ALTER CHANNEL('SYSTEM.DEF.SVRCONN') CHLTYPE(SVRCONN) MCAUSER('mqm')
REFRESH SECURITY TYPE(CONNAUTH)

The process running on Openshift 4 looks like

1000790+     232  0.0  0.1 2308688 45776 ?       Ssl  09:39   0:00 /opt/mqm/bin/amqzxma0 -m QM1 -x -u 1000790000

but in the Openshift 3 it looks like

1000100+    152  0.0  0.0 2324200 33812 ?       Ssl  May03   0:06 /opt/mqm/bin/amqzxma0 -m QM1 -x -u mqm

Another difference are the "capabilties" and the security attributes that the MQ container has on startup.
On Openshift 3:

Capabilities (bounding set): chown,dac_override,fowner,fsetid,setpcap,net_bind_service,net_raw,sys_chroot,audit_write,setfcap
Process security attributes: system_u:system_r:container_t:s0:c0,c15

On Openshift 4:

Capabilities (bounding set): chown,dac_override,fowner,fsetid,setpcap,net_bind_service,net_raw,sys_chroot
Process security attributes: system_u:system_r:container_t:s0:c17,c28

Stacktrace produced by the application:

Caused by: org.springframework.jms.JmsSecurityException: JMSWMQ2013: The security authentication was not valid that was supplied for QueueManager 'QM1' with connection mode 'Client' and host name 'my-mq(1414)'.; nested exception is com.ibm.msg.client.jms.DetailedJMSSecurityException: JMSWMQ2013: The security authentication was not valid that was supplied for QueueManager 'QM1' with connection mode 'Client' and host name 'my-mq(1414)'.
Please check if the supplied username and password are correct on the QueueManager to which you are connecting.; nested exception is com.ibm.mq.MQException: JMSCMQ0001: IBM MQ call failed with compcode '2' ('MQCC_FAILED') reason '2035' ('MQRC_NOT_AUTHORIZED').
        at org.springframework.jms.support.JmsUtils.convertJmsAccessException(JmsUtils.java:286)
        at org.springframework.jms.support.JmsAccessor.convertJmsAccessException(JmsAccessor.java:185)
        at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:507)
        at org.springframework.jms.core.JmsTemplate.browseSelected(JmsTemplate.java:1029)
        at org.springframework.jms.core.JmsTemplate.browse(JmsTemplate.java:991)
        ... 78 more
    Caused by: com.ibm.msg.client.jms.DetailedJMSSecurityException: JMSWMQ2013: The security authentication was not valid that was supplied for QueueManager 'QM1' with connection mode 'Client' and host name 'my-mq(1414)'.
Please check if the supplied username and password are correct on the QueueManager to which you are connecting.
        at com.ibm.msg.client.wmq.common.internal.Reason.reasonToException(Reason.java:531)
        at com.ibm.msg.client.wmq.common.internal.Reason.createException(Reason.java:215)
        at com.ibm.msg.client.wmq.internal.WMQConnection.<init>(WMQConnection.java:424)
        at com.ibm.msg.client.wmq.factories.WMQConnectionFactory.createV7ProviderConnection(WMQConnectionFactory.java:8475)
        at com.ibm.msg.client.wmq.factories.WMQConnectionFactory.createProviderConnection(WMQConnectionFactory.java:7815)
        at com.ibm.msg.client.jms.admin.JmsConnectionFactoryImpl._createConnection(JmsConnectionFactoryImpl.java:303)
        at com.ibm.msg.client.jms.admin.JmsConnectionFactoryImpl.createConnection(JmsConnectionFactoryImpl.java:236)
        at com.ibm.mq.jms.MQConnectionFactory.createCommonConnection(MQConnectionFactory.java:6016)
        at com.ibm.mq.jms.MQQueueConnectionFactory.createQueueConnection(MQQueueConnectionFactory.java:111)
        at com.ibm.mq.jms.MQQueueConnectionFactory.createConnection(MQQueueConnectionFactory.java:187)
        at org.springframework.jms.support.JmsAccessor.createConnection(JmsAccessor.java:196)
        at org.springframework.jms.core.JmsTemplate.execute(JmsTemplate.java:494)
        ... 80 more
    Caused by: com.ibm.mq.MQException: JMSCMQ0001: IBM MQ call failed with compcode '2' ('MQCC_FAILED') reason '2035' ('MQRC_NOT_AUTHORIZED').
        at com.ibm.msg.client.wmq.common.internal.Reason.createException(Reason.java:203)
        ... 90 more

Any idea on what the issue could be?