This is because the WIFI you are connected to is not connected to the data network, so even if you are connected to this WIFI, you can't surf the Internet.

Unless it is the public network of some service places, it is necessary to verify the mobile phone or pay attention to WeChat. If there is a time limit, ask the clerk, such as banks, KFC and restaurants.

Or you can try to ignore this network and re-enter the WIFI password.

If it is your own router, you can reconfigure it.