12 SNZB-01P buttons lose association after coordinator restart — only 2-3 work each time

[popolski]

Hi,

I'm running Zigbee2MQTT v2 on Windows with a CC2652P dongle (zstack adapter, COM3). I have 12 Sonoff SNZB-01P buttons paired as end devices. Everything works perfectly during a session, but after every restart of Zigbee2MQTT, only 2-3 buttons respond — the others are silent until I long-press their pairing button to force a rejoin.

Setup:

Zigbee2MQTT v2, zigbee-herdsman 10.4.0
CC2652P dongle, zstack adapter
12 × Sonoff SNZB-01P (all end devices, no routers)
Windows 11, Mosquitto broker
permit_join: true (permanent, time: 0)
network_key hardcoded in configuration.yaml
Graceful shutdown via REST API (POST /api/shutdown), waiting for node.exe to exit before killing
What I've confirmed:

coordinator_backup.json IS updated after graceful shutdown (file modification date changes)
All 12 devices are present in the backup
permit_join is permanently open
Normal button press after restart does nothing — no log entry in Z2M
Long-press on pairing button fixes the specific button for that session
My question:
It seems like the SNZB-01P does not attempt auto-rejoin after a failed message send — it just goes back to sleep. Is this correct behavior for this device?

Would adding a mains-powered Zigbee router (e.g. Sonoff S26R2) fix this? My understanding is that end devices would associate to the router instead of the coordinator, and the router maintains its own child table independently — so even if the coordinator loses state, the router still knows its children. Is this correct?

Any experience with this setup appreciated. Thanks!