Not automatic charging

Hi,
When my robot is finished cleaning. He goes to the dock and clean himselfs. Till there it's fine. But then he stays 1cm out of the dock and doesn't charge.
When I click on the app on the home button. He goes out of the dock and in again and then he is chart.
Anyone an idea what is causing this.
It's from the beginning that I bought it new, he is not charging on his own.

Hello,

If the base station is placed on a slope (not level), please move it to a flat surface and make sure the ramp mat is properly extended to avoid affecting the robot’s ability to dock and charge correctly.

You can also check whether there are any water stains on the driving wheels or in front of the base station. We recommend wiping the wheels and the area in front of the base station in time.

Make sure the base station is placed away from sources of signal interference, such as routers or televisions. There should also be no reflective surfaces around the base station, such as mirrors, windows, or other shiny objects.