You can follow the steps below to have a try and resolve this:
1. Make sure the computer is connected to WiFi.
2. Ensure Assistant for Android is installed on the device. If not, connect the device with PC via USB cable and MobiKin Assistant for Android app will be installed onto your device automatically.
3. Open the app on the device and scan QR code.
4. Choose the correct computer on the device to get connected. If it doesn't work, you can try to connect it through a USB cable