Environment
Home Assistant with a Thread border router and several Matter-over-Thread plugs.
What happens
The plugs remain offline after the network returns until each device is power-cycled.
What I have tried
Restarted Home Assistant and confirmed that the Thread radio is detected.
I would appreciate advice on how to identify the root cause without risking existing data or configuration.
Verified community troubleshooting
A safe way to narrow this down is to change one variable at a time.
Likely cause: The border router advertises stale IPv6 routes or changed its operational dataset.
What I would try: Confirm a single preferred Thread dataset, restart the border router before Home Assistant and recommission only devices with mismatched credentials.
If this is a production system, test the change during a maintenance window.
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