We saw you have deleted this standalone sensor.
If you want to move the stand alone sensors to a zone, please go to the home page. There is a drop down menu and please select your Sprite controller, then go to Add a Product-> Plant sensor and then select the zone and complete the following procedures to add the sensor. You will need to press the button 6 times on the back of the sensor to change its mode to Setup mode (light blinking slowly).
Please let us know if you want to delete the "Plant Sensors" in the drop menu and we can help you delete it from the server side.