Why my IP camera drops out wifi connection after dark?

[sma888]

I have installed two IP cameras at the front of my house having one pointing at the front door (camera A) and the other pointing at the driveway (camera B). Both cameras connect to the router via wifi connection and each runs their own power cable to a power supply inside the house. The problem is camera A always lost wifi connection when day light disappears and darkness set in. It happens around 6pm during winter and 8:15pm during summer. The next morning Camera A automatically reconnects to the wifi when day light appears. I have ruled out the following possible causes:

1. Camera A lose power after dark. This is not true because the IR light turns on after dark which indicates power supply is still on. 

2. Camera A is malfunction. This is not true because I swap the two cameras and the same thing happens to the other camera pointing at the front door.

3. Wifi setup is incorrect. This doesn't explain why it works during day time and not night time.

Can someone explain:

1. Why wifi connection of a IP camera is sensitive to light?

2. Why this only happens when it is pointing at the front door and not pointing at the driveway?

[cf4]

At night the led lights are turned on. This results in the camera drawing more power from the power source which if you are powering the  camera's from a low voltage DC source the drop in voltage dje length of cable might be enough to stop the WiFi from working. You can test this gheory by swktching the infra red lights off in the camera settings and see if camera still disconnects.

[sma888]

Thanks cf4. I shall give it a try tonight and see if the IP camera will regain wifi connection after I turn the IR light off.

[ProfessorPhone]

It possibly could be  interference from a neighbour's modem which is on the same WiFi channel, and they only turn their modem on at night.   Just a possibility.