（1）Restart the router and mobile, reset the device, and re-add.
（2）Confirm the WIFI can be connected to the Internet stably.
Confirmation method: after connecting to WiFi, open the website with the 4G network turned off. Ensure that you can surf online normally.
（3）Change the internet and re-add the camera.
If there is no other WIFI to change, use the mobile hot spot as the router, reset the device, and then re-add.