See this discussion: https://vmware.slack.com/archives/C055BSG8E/p1709799850327309 `queue_master_locator` only applies to mirrored classic queues, which will be removed in RabbitMQ 4.0, so this policy setting should be removed as well. `queue_leader_locator` is the setting to use for QQs and Streams. ### Describe the solution you'd like Remove `queue_master_locator` setting.