I have of the same dusk to dawn fixtures in the walkway walls leading up to my entrance. When it gets dark it appears that only one goes on. Is it possible that the light from this fixture is telling the other fixture that it is still light outside. The photo sensor for both fixtures are in the same spot, on the top of the fixture. If I turn the lights off then wait a few seconds before turning them back on then both lights are now on. In the morning they both turn off with no problem. Any suggestions as to what I can do to alleviate the problem in the evening.