When subscribing to data from a device with the subscription having QoS 0, cleanSession=true and even with a new client id, the last messages (on each topic matching the subscription) are delivered. For example, subscribing to company/load/+/100 gives me the last four messages which were published to company/load/a/100, company/load/b/100, company/load/c/100 (but never more than one message for each topic).
I am unable to duplicate this behavior without the retain flag set on the published messages. Can you provide a small app that demonstrates the problem?
If the published messages have the retain flag set then this is the expected behavior.