One of these will definitely work
My phone won't connect to wifi / doesn't detect available wifi network – Solved
Troubleshooting network-related issues on Android can be quite a hassle, but not if you know the steps to take to fix the problem. In this tutorial, we highlight 11 possible solutions that you can try when your Android phone won’t connect to Wi-Fi.
If your phone doesn't detect the network or the connection drops intermittently, you may be able to fix the issue by turning Wi-Fi (on your phone) off and back on.
Go back to the Wi-Fi settings menu and try connecting to the network again.
