@TaufanSuha 

Sorry for the trouble caused by the camera. Please kindly help verify the below information and we will try to investigate this offline issue ASAP:

1. What is your network topology and what is the brand & model number of your host router? Do you mean the router will sometimes restart or you turn it off then on?

2. What is the brand of the other cameras or smart devices that will connect automatically when the router restarts?

3. When the router is back on, how about the Tapo cameras status, are their LEDs solid green or flashing green? If they are all solid green, which means they can connect to the router automatically when the router is back.

But if you still cannot view them on the Tapo app even when the LEDs are solid green, please confirm you are viewing them in the local network or from an outside one or via 4G cellular data. Local means your phone is connected to the same wireless as the cameras connected to, you may disable the 4G cellular on the phone and confirm.