As of version 7.1 of MQ, the default security configuration is more restrictive and as such will probably need to be modified further before you can get a successful connection via a channel that has mcauser('mqm').
...
{qmgr} Queue Manager Name
{User} The MQ user being used by Lamaxu
Enable Queue Manager Monitoring and Statistics
The MONQ and MONCHL must be set to MEDIUM or higher to enable MQ to publish the Status and event information.
Use the MQSC commands below to modify the queue manager configuration and restart the LAMAXU agent.
ALTER QMGR CHLEV(ENABLED) +
MONCHL(MEDIUM) +
MONQ(MEDIUM) +
PERFMEV(ENABLED) +
STATCHL(MEDIUM) +
STATQ(ON) +
FORCE