Let's try excluding the sensor first. 

Exclusion is just like a reset, and can help with a variety of configuration and connectivity issues. Devices don't need to be included properly to be able to be excluded. 

In your SmartThings app:

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 Z-Wave Exclusion
5. While the app is searching for a device, click the Z-Wave button (tamper switch) on the device 3 times as quickly as possible
6. The app will indicate when the device is successfully removed. Tap Done

Once exclusion is completed, try including the sensor to the system again.

If you're still unable to include your sensor after excluding it, here are some other things to try:

• Try the exclusion process again! Sometimes commands from the first run aren't registered correctly, so it's worth trying. 
• Try the inclusion process again, only this time instead of clicking the tamper switch 3 times, click it 4-5 times as quickly as possible.
• Try including in a non-secure mode if you attempted adding it securely the first time.
• Bring the sensor closer to SmartThings to verify it's not a range issue. 
• Double check that the device is powered and that the batteries are oriented properly. 

But if you're still seeing issues with the exclusion/inclusion process no matter what you try, let us know! Our team will be happy to help.