Likely causes
- Hub rebooted faster than the devices re-joined the mesh
- Devices with weak batteries failed to rejoin
- Network name or IP change after the outage
- Corrupted local database after an unclean shutdown
- Router took longer than the hub to come online
Quick checks
- Wait ten minutes and refresh the app before reacting
- Check whether the hub is online in the app
- Confirm the router and internet came back first
- Look for devices that also lost battery level readings
Step-by-step fix
Reboot the router first, then the hub
Wait for the mesh to re-form and refresh the app
Re-add only the devices that stay offline
Update hub firmware
Add a small UPS for the hub and router to avoid unclean shutdowns