Thousands of duplicate message and invalid client ID messages; many messages not consumable

After a complicated sequence of administrative events involving a mesh-connected pair of A-MQ 6.3 brokers, the log shows thousands of messages related to duplicate messages and invalid client ID in the network connector. Consumers are unable to consume about a thousand messages, and these messages are not visible in the Hawtio console. However, no messages are shown as in flight and, when the message store is copied to a test system, the messages are both visible and consumable.