This is most likely due to the timer being on the far range of the WiFi signal broadcasted by your home’s WiFi router. The best way to check this is to open the mobile application when it is connected and select the timer from the list of timers. Once you are inside the expanded timer view, you can select the tab with the icon showing a WiFi signal. If the signal strength indicator has very few bars, this confirms the timer is on the edge of the WiFi range. If possible, move the timer closer to the WiFi router. If this is not possible due to wiring or its location outdoors, the next best option is to attempt to move your WiFi router closer to the timer. If the timer is unable to communicate with your home WiFi router at all, place the WiFi Module in AP mode and connect your mobile device directly to the WiFi Module’s broadcasted AP signal (Network Name: “RainBirdXXXXXX” where XXXXXX is the last 6 digits of the WiFi Module’s serial number found on the back of the device).