If QMGR is restarted then APMIA data is not updated, it just reports in the console with false data.
Example: We had one incident where APM didn't alert for current queue depth of the queues and in APMIA showed that queue on zero .
So I restarted the Agent. After that APMIA picked up the current data from MQ side.
Release : SAAS
If it is set to shared, then some of the resources will be shared by both client (in this case our agent) and qm process.
That's the reason it is locking the process until agent is also restarted. So this is expected behavior when using MQ bindings mode for client connection.