I have changed the battery with 3 different new batteries. The blue light comes on and blinks when it closes. I moved the magnet and made sure it was close enough. It was working for a few months then quit. It tells me that my back door entry sensor is not responding. Please help. I think I may have

I have changed the battery with 3 different new batteries. The blue light comes on and blinks when it closes. I moved the magnet and made sure it was close enough. It was working for a few months then quit. It tells me that my back door entry sensor is not responding. Please help. I think I may have