Hub 2 lightLevel changeReport webhook events never delivered despite successful registration

[hey-po-in-the-word]

Environment

• Device: Hub 2 (WoHub2), firmware V4.1-3.0
• API version: v1.1
• Region: Japan
• Receiving endpoint: HTTPS, valid Let's Encrypt cert (TLS 1.3), reachable and independently verified (see below)

Summary

setupWebhook returns a success response (statusCode: 100) and queryWebhook/queryDetails confirms the registration (enable: true, fresh createTime). However, real lightLevel changeReport events for the Hub 2 are never delivered to the registered endpoint, even though:

• REST polling (GET /devices/{deviceId}/status) shows lightLevel changing in real time (confirmed multiple times over a ~1 hour window)
• The SwitchBot app's own push notification (in-app automation trigger for a light-level threshold) fires correctly for the same real-world event
• The app's own history log for the device shows continuous, fresh readings (up to the same day, no gap)

This confirms the cloud is receiving and processing the sensor data correctly — the failure is isolated to the webhook delivery step specifically.

Steps to reproduce

1. POST /v1.1/webhook/setupWebhook with deviceList: "ALL" → success
2. POST /v1.1/webhook/queryWebhook (queryDetails) → confirms enable: true, correct createTime
3. Wait for a real lightLevel change on the Hub 2 (confirmed independently via polling)
4. No POST ever arrives at the registered endpoint for that event

Evidence our receiving endpoint is healthy

• A manual test POST to the exact same registered URL is received, logged, and responded to (200) within ~65ms
• The only requests that "succeed" are either our own manual test POSTs, or what appear to be SwitchBot's one-time post-registration test push (deviceMac: "TESTMAC" / similar placeholder), never a real device event
• TLS chain verified independently (valid cert, TLS 1.3, complete chain)

Timeline

• 2026-08-05 23:20 — delivery silently stopped (previously working)
• 2026-08-08 — noticed after 3 days of silence; deleteWebhook → setupWebhook → registration succeeds, one placeholder test event received, then zero real events again
• 2026-08-11 — repeated deleteWebhook → setupWebhook → same pattern: registration succeeds, zero real events over several confirmed real light-level changes within the same hour

Question

Is there a known issue with changeReport delivery specifically for Hub 2 lightLevel events, or an account/region-level delivery problem? Related reports that look similar: #384, #345, #407, #368.

Happy to provide additional logs (redacted) or a live reproduction window if useful.