Also the Iphone 44turns offline without clear reason why.
I have three different telephones that are connected to 2 different routers and all three behave the same: off line every now and again (sometimes for days).
You see your camera offline 7007 when your Camera has been powered down, disconnected, logged out, or simply crashed. Please run a quick Camera Health Check to see if the power supply/connection can be improved:
Also, please avoid pressing home button or power key after you set up Camera. Instead, you can tap the Lock icon on the bottom right corner. What’s more, please try Guided Access to ensure your Camera(iOS) not deter by activity from other applications. You can see how here: