There are a few reasons a device can drop offline its network or stop responding to commands - let's see what we can do to help.

• The ZEN34 Remote Switch has a range of up to 250 feet line of sight - but this range can be shortened by interferences like glass or metal elements, thick walls, or large furniture. If your ZEN34 frequently disconnects or stops responding, the first thing we would recommend is testing it closer to your Z-Wave controller to rule out any range or interference issues.
• Your hub establishes the communication route with the remote so it's possible it just hasn't found the ideal path to talk to the ZEN34. If your controller supports a way of refreshing your Z-Wave mesh network, you could try doing that so your hub finds the best way to the Remote Switch - especially if you've recently moved it to a new location.
• If your Z-Wave network doesn't have a lot of signal repeating devices on it, you may need to try installing a Z-Wave signal repeater (or any non-battery powered Z-Wave device) between the location of the ZEN34 and your hub to extend the mesh network so your hub can communicate easier with your device.
• Your ZEN34 could be losing power - try fresh batteries to rule out any power related issues.
• If none of these troubleshooting steps help or your ZEN34 only works when closer to the hub, then you may need to try a location that's closer than where the remote is currently installed.

We'd be happy to help with additional troubleshooting if your ZEN34 is still having trouble being controlled from your Z-Wave controller.