If your ZEN58 Low Voltage XS Relay is successfully included but shows offline, it may be a range or connectivity issue. 

Using the Network Repair feature in the SmartThings app can refresh your mesh network's connections. 

Network Repair

Steps for Network Repair below:

1. Open your SmartThings app and locate your SmartThings hub under Devices. Tap the hub to see the device details. 

2. Tap the three dots in the upper right hand corner and tap Settings

3. Tap Z-Wave Utilities 
4. Tap Repair Z-Wave Network 
5. Tap Start Repair 

Wait until you see the "Z-Wave Network Repair finished" message before sending any commands to your ZEN58 Relay (up to 15 minutes). When this is finished, try to include the relay back into your network.

More Troubleshooting Steps

If Network Repair doesn't help:

1. Exclude it from within direct range of the hub. Re-include it from the same range. If the relay is then included successfully and the connection remains steady, it is possible there are too many interferences between the hub and the relay, or the previous spot may be out of SmartThings' range.
2. Try again to exclude and re-include the relay from the installation location directly. It's possible that SmartThings has not yet found the most efficient communication route to the ZEN58 Relay. This can occasionally happen when you include a device near the hub and then move it away to be installed. 
3. Try a factory reset on the device and then try including it again.
4. Add another mains-powered Z-Wave device (plugged in or hardwired) between the desired ZEN58 installation location and the hub, then run the network repair again so the hub can use the new device to reach the ZEN58.

If you need additional assistance, please don't hesitate to reach out!