The following are the reasons that the APP can't build a connection with the device after scanning the QR code on its nameplate:

1. The device is not enabled for HTTP access.

2. The 2.4G Wi-Fi access point function of the device has been turned off.

3. The Wi-Fi connection parameters of the device are not factory settings.

4. The Wi-Fi signal is weak, such as far away from the device or the device is not connected to the Wi-Fi antenna.

When you can't connect to the device by scanning, please try to connect to the device's Wi-Fi manually or use the network cable to configure the device's networking parameters.