Please check if your WiFi signal is strong enough and stable in the room where the baby monitor is positioned. You can do this by downloading a speedtest app. When your download and upload speed at the location of your baby monitor is below 2 Mbps, this will hamper the connection. A WiFi repeater can help you improve your WiFi signal strength.
If the WiFi status light is solid green and the connection still keeps getting lost then the problem may be with the internet connection of your smart device. Please check the WiFi strengh on your smart device or check if your 3G or 4G speed is ok, by e.g. trying to watch a Youtube video.