C7 - Devices keep dropping and/or not joining the C7

Just purchased a C7 recently (early March) for a friend. Unfortunately, the friend has been in/out of the hospital over the last year and was unaware that she was having problems with devices dropping from the network. The devices that I'm trying to join are Sengled light bulbs and Third Reality motion sensors.

1 - I upgraded to the latest platform version to no avail hoping that platform version will resolve issue.
2 - Tried to delete and join the devices again - In some cases, the devices will join but you can no longer control and in order cases, the devices will not join at all.

3 - In most cases, the logs will not even show zigbee discovery in process.

While this is still under warranty, should I return or are there other solutions I should try?

The issue is lack of repeaters causing a weak mesh. Sengled bulbs do not repeat (this is good) and neither do those motion sensors. You need to add several mains based devices to have repeaters to strengthen your mesh.

You can use these as repeaters


OK -- thank you -- will try that. (note: Didn't think I would need the repeaters unless I had over 32 devices -- lesson learned.)