Why does the camera go offline every evening and come back online in the morning?

The camera has the IRCUT automatic switchover; this allows the camera to switch to Night vision automatically when it gets dark.

 This sounds like the camera's night vision mode is not able to function; this can happen if the camera is not getting sufficient power or if the hardware is faulty.

 We request you to connect the camera to a different power socket and also try using a different power cable/adaptor and check if the issue persists.