AirCon 0.3.17 unavailable after HA Core 2026.5.3 - notifier.py keepalive fails

[JoMa20]

Hi,

After updating Home Assistant Core to 2026.5.3, my HiSense Air Conditioners add-on 0.3.17 marks the AC entity as unavailable.

Symptoms:

• The entity becomes available briefly after restarting the add-on.
• After around 20-25 seconds, it becomes unavailable again.
• After a full Home Assistant host restart, the entity remains unavailable.
• The official HiSense/ConnectLife app still works.

Add-on configuration:

• Add-on version: 0.3.17
• mqtt_host: core-mosquitto
• mqtt_port: 1883
• mqtt_user: aircon
• port: 1888
• local_ip: 192.168.1.150
• log_level tested with DEBUG and INFO

Main log error:
D0520 22:12:04.412 notifier.py:112] [KeepAlive] Sending POST http://192.168.1.247/local_reg.json {"local_reg": {"ip": "192.168.1.150", "notify": 1, "port": 1888, "uri": "/local_lan"}}
E0520 22:12:04.437 notifier.py:121] Failed to connect to 192.168.1.247, maybe it is offline?

Checks performed:

• AC IP 192.168.1.247 responds to ping from Windows.
• Port 80 on 192.168.1.247 is reachable from Windows.
• Home Assistant terminal can ping 192.168.1.247.
• Home Assistant terminal can connect to http://192.168.1.247/local_reg.json.
• GET /local_reg.json returns 404, which seems expected for GET.
• Empty POST to /local_reg.json returns 400, which seems expected without payload.
• Manual POST with the same local_reg payload used by the add-on returns HTTP/1.1 202 Accepted.
• Add-on listener on http://192.168.1.150:1888/local_lan responds with aiohttp 404, so the listener is reachable.
• MQTT client aircon connects successfully to Mosquitto.
• MQTT commands are received by the add-on, for example:
  MQTT message Topic: hisense_ac/a0c9a00de98e/operation_mode/command, Payload b'off'
• Setting local_ip explicitly to 192.168.1.150 does not fix the issue.
• Changing log_level DEBUG/INFO does not change the behavior.
• Full Home Assistant system restart does not fix the issue.

Conclusion:
Network, MQTT, local_ip and local_reg endpoint seem OK. The issue appears to be inside AirCon notifier.py / KeepAlive handling, or in MQTT availability handling after Home Assistant Core 2026.5.3.

This looks related to issue #303:
"E0213 13:35:08.688 notifier.py:121] Failed to connect to ip, maybe it is offline?"

Any idea what else I can test or whether this is a known compatibility issue with recent Home Assistant Core versions?

Additional log after full Home Assistant system restart and with local_ip explicitly set to 192.168.1.150:

D0520 22:15:42.277 notifier.py:112] [KeepAlive] Sending POST http://192.168.1.247/local_reg.json {"local_reg": {"ip": "192.168.1.150", "notify": 1, "port": 1888, "uri": "/local_lan"}}
E0520 22:15:42.297 notifier.py:121] Failed to connect to 192.168.1.247, maybe it is offline?
D0520 22:15:42.299 notifier.py:85] [KeepAlive] Waiting for notification or timeout

E0520 22:17:14.090 notifier.py:121] Failed to connect to 192.168.1.247, maybe it is offline?
I0520 22:17:19.551 mqtt_client.py:37] MQTT message Topic: hisense_ac/a0c9a00de98e/operation_mode/command, Payload b'off'
E0520 22:17:21.570 notifier.py:121] Failed to connect to 192.168.1.247, maybe it is offline?

This shows that MQTT commands are still received by the add-on, but the KeepAlive/local_reg part continues to fail repeatedly.

[JoMa20]

Update :

After power-cycling the Fujitsu AC unit from the breaker and rebooting the router, the module
started responding again.
I disabled the HACS Hisense Air Conditioner integration and enabled only the original AirCon add
on.
Now AirCon seems stable again. The add-on log shows successful local LAN communication:
POST /local_lan/key_exchange.json HTTP/1.1" 200
GET /local_lan/commands.json HTTP/1.1" 200
POST /local_lan/property/datapoint.json?...status=200 HTTP/1.1" 200
Decrypted property updates are received correctly.
Current hypothesis:
The Fujitsu/FGLair/Ayla module may have become stuck or saturated after repeated failed
keepalive/local_reg attempts or after testing multiple integrations. After a full power cycle,
the original AirCon add-on works again when it is the only active integration.
I will monitor stability.