The router's wireless signal frequency band needs to be set to 2.4GHz. Because smart appliances only support WiFi connections in the 2.4GHz band, if your router's wireless signal frequency band is set to 5GHz, smart appliances cannot be connected.
Therefore, the wireless signal frequency band of the router needs to be set to 2.4GHz.
Depending on the brand and model of the router, the setting method is different. You can check the router manual or find the setting procedure on the relevant forum. At the same time, if the router supports dual-band WiFi work at the same time, you can turn on 2.4GHz and 5GHz at the same time, which can not only support the connection of smart home appliances, but also improve the network speed and stability. In addition, if the smart home appliance cannot connect to WiFi in the 2.4GHz band, you can consider updating the firmware of the smart home appliance to solve the problem.