The leak detection module is designed to flash the blue LED when the attached membrane senses water. This function is a normal occurrence; however, the alert indicates the presence of water and should be checked as soon as possible to see what the source is and whether a repair is needed to prevent further leaking and subsequent damage.
The blinking and beeping will continue until either the membrane is disconnected - or - the membrane is dried.
A false alarm may occur if the membrane's conductive side is touching a wide enough area of a conductive surface to bridge the wavy black tracks. If you find that this is the case, move the membrane off of the conductive surface, or flip the membrane over so that the black tracks are facing away from the conductive surface.