What happened?

1. EMQX version v5.8.8
2. Authentication method uses client username, Client ID, and password for authentication.
3. The two devices are RT65012 and T77523; their respective monitored Topics are iot/device/RT65012 and iot/device/T77523.
4. Both devices use the same authentication account; in Cluster Configuration - MQTT Configuration, 'Use username as Client ID' is turned off.
5. Problems encountered:
   5.1 RT65012 does not appear under Monitoring - Clients, while T77523 displays normally.
   5.2 After T77523 comes online, checking its subscribed topics, it initially shows:

The captured logs are as follows:
2025-12-17T09:38:35.331409+00:00 [MQTT] [email protected]:55366 msg: mqtt_packet_sent, packet: SUBACK(Q0, R0, D0, PacketId=1, ReasonCodes=[0]), username: jixieshi
2025-12-17T09:38:35.362399+00:00 [MQTT] [email protected]:55366 msg: mqtt_packet_received, packet: SUBSCRIBE(Q1, R0, D0, PacketId=2 TopicFilters=[iot/device/T77523(#{nl => 0,qos => 0,rap => 0,rh => 0})]), username: jixieshi
2025-12-17T09:38:35.362591+00:00 [AUTHZ] [email protected]:55366 msg: authorization_module_ignore, action: SUBSCRIBE(Q0), authorize_type: client_info, module: emqx_authz_client_info, topic: iot/device/T77523, username: jixieshi
2025-12-17T09:38:35.362698+00:00 [AUTHZ] [email protected]:55366 msg: authorization_matched_allow, action: SUBSCRIBE(Q0), authorize_type: file, module: emqx_authz_file, topic: iot/device/T77523, username: jixieshi
2025-12-17T09:38:35.362759+00:00 [SUBSCRIBE] [email protected]:55366 msg: subscribe, sub_id: T77523, sub_opts: [nl: 0, qos: 0, sub_props: [], rap: 0, rh: 0], topic: iot/device/T77523, username: jixieshi
2025-12-17T09:38:35.362934+00:00 [MQTT] [email protected]:55366 msg: mqtt_packet_sent, packet: SUBACK(Q0, R0, D0, PacketId=2, ReasonCodes=[0]), username: jixieshi
2025-12-17T09:38:35.397575+00:00 [MQTT] [email protected]:55366 msg: mqtt_packet_received, packet: PUBLISH(Q0, R0, D0, Topic=iot/service/deviceid, PacketId=undefined, Payload(text)={"cmd":"declare","type":"device","sn":"T77523","ip":"192.168.10.2","version_code":"20000015","version_name":"7.8.7","timestamp":1765964313,"token":""}), username: jixieshi
2025-12-17T09:38:35.397734+00:00 [AUTHZ] [email protected]:55366 msg: authorization_module_ignore, action: PUBLISH(Q0,R0), authorize_type: client_info, module: emqx_authz_client_info, topic: iot/service/deviceid, username: jixieshi
2025-12-17T09:38:35.397784+00:00 [AUTHZ] [email protected]:55366 msg: authorization_matched_allow, action: PUBLISH(Q0,R0), authorize_type: file, module: emqx_authz_file, topic: iot/service/deviceid, username: jixieshi
2025-12-17T09:38:35.397818+00:00 [PUBLISH] [email protected]:55366 msg: publish_to, payload_encode: text, topic: iot/service/deviceid, username: jixieshi, payload: {"cmd":"declare","type":"device","sn":"T77523","ip":"192.168.10.2","version_code":"20000015","version_name":"7.8.7","timestamp":1765964313,"token":""}
2025-12-17T09:38:45.826103+00:00 [RULE_SQL_EXEC] [email protected]:55366 msg: rule_activated, environment: [], input: [node: emqx@emqx-core-7f8f9cf999-1.emqx-headless.sports-prod.svc.cluster.local, reason: discarded, timestamp: 1765964325826, peername: 10.206.16.6:55366, sockname: 172.16.0.83:1883, event: client.disconnected, username: jixieshi, proto_ver: 4, client_attrs: [], clientid: T77523, proto_name: MQTT, connected_at: 1765964315293, disconn_props: [User-Property: []], disconnected_at: 1765964325825], rule_id: Device_Disconnected_WH_D, rule_trigger_ts: [1765964325826], username: jixieshi
2025-12-17T09:38:45.826321+00:00 [RULE_SQL_EXEC] [email protected]:55366 msg: SQL_yielded_result, result: [node: emqx@emqx-core-7f8f9cf999-1.emqx-headless.sports-prod.svc.cluster.local, reason: discarded, timestamp: 1765964325826, peername: 10.206.16.6:55366, sockname: 172.16.0.83:1883, metadata: [rule_id: Device_Disconnected_WH_D], event: client.disconnected, username: jixieshi, proto_ver: 4, client_attrs: [], clientid: T77523, proto_name: MQTT, connected_at: 1765964315293, disconn_props: [User-Property: []], disconnected_at: 1765964325825], rule_id: Device_Disconnected_WH_D, rule_trigger_ts: [1765964325826], username: jixieshi
2025-12-17T09:38:45.826388+00:00 [BRIDGE] [email protected]:55366 msg: bridge_action, action_info: [name: Device_Disconnected_WH_D, type: http], rule_id: Device_Disconnected_WH_D, rule_trigger_ts: [1765964325826], username: jixieshi

What did you expect to happen?

I hope to resolve the following two issues:

1. RT65012 should display normally in the client list, similar to T77523.
2. The topic iot/device/RT65012 should appear in the topic list of the RT65012 client, not in the T77523 client, which ultimately causes iot/device/RT65012 to overwrite the iot/device/T77523 topic.

How can we reproduce it (as minimally and precisely as possible)?

No response

Anything else we need to know?

No response

EMQX version

OS version

# On Linux:
$ cat /etc/os-release
# paste output here
$ uname -a
# paste output here

Log files

T77523 (1).zip

This issue was automatically translated from Chinese.