There are two methods available to disable a Wi-Fi Direct (Simple AP) connection; you can disable all connections by using the control panel, or disable each connection from the computer or the smart device.
When you want to disable all connections, select 
> Wi-Fi Direct > Start Setup > 
Disable Wi-Fi Direct.
When Wi-Fi Direct (Simple AP) connection disabled, all computers and smart devices connected to the scanner in Wi-Fi Direct (Simple AP) connection are disconnected.
If you want to disconnect a specific device, disconnect from the device itself instead of the product. Use one of the following methods to disconnect the Wi-Fi Direct (Simple AP) connection from the device.
Disconnect the Wi-Fi connection to the scanner's network name (SSID).
Connect to another network name (SSID).