AIX remote monitoring fails with error "Could not process metric query command: . Error: null" (4242970)

UnixAgent is monitoring AIX using a remote FglAM. With debug logging enabled, we see the following error logged within the UnixAgent log:

ECHO    <HostAgents/5.6.4/UnixAgent/MonitorOS@SERVER> DEBUG [Quartz-20206] com.quest.glue.core.remoteconnection.SSHGanymedConnectionImpl - Executing remote cmd '/usr/bin/env LC_ALL=C /tmp/server8403b6-7765-474f-ad1a-c05bb4210bde-HostAgents-5-6-4-UnixAgent-MonitorOS-SERVER-quest_perfstat.bin --use_sudo /usr/bin/sudo'
ECHO    <HostAgents/5.6.4/UnixAgent/MonitorOS@SERVER-agent> DEBUG [Quartz-20206] com.quest.remoteos.collectors.AbstractUnixCollector - An unexpected error occurred which may cause undesired behavior. You may want to contact Quest Software customer support if you see this error again: should never time out
java.util.concurrent.TimeoutException: timed out waiting for command to complete
 at com.quest.glue.core.remoteconnection.SSHGanymedConnectionImpl.execute(SSHGanymedConnectionImpl.java:495)
 at sun.reflect.GeneratedMethodAccessor41.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
ECHO    <HostAgents/5.6.4/UnixAgent/MonitorOS@SERVER-agent> ERROR [Quartz-20206] com.quest.remoteos.collectors.aix.AIXCollector - Could not process metric query command: . Error: null