Step 1Go to the app settings and change the region to your local region, do not select China mainland (in my case I changed to the US (Recommended).
Step 2If you are using an android phone, go to the phone settings and enable the location permission.
Step 3If your Wi-Fi password contains special characters like questions mark, colon, change the password without them to have a try.
Step 4If the app says it could not connect to the public Wi-Fi, it is probably because your Wi-Fi encryption mode is WEP. You should log in to your router settings page (192.168.1.1 or 192.168.0.1) and change the encryption mode to WPA or WPA2.
Step 5You could try to reset Wi-Fi by holding the «recharge» button and the «spot cleaning» button for 5 seconds until you hear a voice prompt.
* Please notice the vacuum could not connect to 5GHz Wi-Fi.
Notice: Please keep your eye on Wi-Fi indicator light under the cover of the device. It will flash with higher frequency than normal status when it is trying to connect wifi and become solid when it is connected. Sometimes app may show error after connecting steps finish, but the Wi-Fi indicator light becomes solid and the device is actually connected to Wi-Fi successfully. In this situation, please close the app and run it again to see if the robot is on the list of app.
We hope it will help you. Enjoy your life with the Roborock S5!