When the controller is in AP mode, the LED flashes very rapidly (2-4Hz). When it’s trying to connect but not connected yet, it flashes more slowly (0.5 to 1Hz). If it has connected to a WiFi before and lost connection, it will try to re-establish connection, so if you see a slow flashing pattern, it means it lost connection and is trying to re-connect. It could be due to WiFi signal strength is weak.