I had a problem for a year or more that I finally solved. An Amcrest "eyeball" camera on one side of my house would continually "go darker" and then lighten up cyclically at night. The cycle time was 2-3 minutes IIRC. I tried swapping with other cameras of the same type, but the problem persisted. The camera image was fine during daylight hours.
I eventually concluded that the camera was reacting to a powerful strobe light on a radio tower about 2 miles away, but the timing didn't seem to agree. Lacking any other explanation, I lived with it for a long time.
I became suspicious of the LED porch light on my neighbor's house, which was normally on all the time at night. When the light was left off, the camera image was steady. With my neighbor's consent, I replaced the LED bulb with a new one of about the same wattage. The problem went away. Apparently, the old bulb was shifting light levels in a way that not visible to the eye, but was affecting the light sensors on the camera.
Recently, I had a 2nd example of this with a LED bulb on my own house.
I eventually concluded that the camera was reacting to a powerful strobe light on a radio tower about 2 miles away, but the timing didn't seem to agree. Lacking any other explanation, I lived with it for a long time.
I became suspicious of the LED porch light on my neighbor's house, which was normally on all the time at night. When the light was left off, the camera image was steady. With my neighbor's consent, I replaced the LED bulb with a new one of about the same wattage. The problem went away. Apparently, the old bulb was shifting light levels in a way that not visible to the eye, but was affecting the light sensors on the camera.
Recently, I had a 2nd example of this with a LED bulb on my own house.