Android Cannot Scan a Wi-Fi Network

Reason
There may be two reasons as to why your Android cannot scan a network automatically. The first reason may be that the network you are trying to connect to could be Ad-Hoc in nature. As most of the Android phones are not configured to work on Ad-Hoc networks but on access points, they don’t scan them.
The second reason may be that the Wi-Fi network you are trying to connect to might be hidden for security reasons.
Solution
By default, Android does not support Ad-Hoc Wi-Fi network but many developers patch the wpa_supplicant file on Android in order for them to work. If you do a quick Google search you will be able to find if there’s a fix available for your device but the fix can only be performed on a rooted phone. Furthermore, don’t forget to back up your original wpa_supplicant file if at all your phones goes into foreclose or boot loops.

If the problem is with the hidden network, you can try to add the network manually. In Android Wi-Fi settings open menu and tap to add a network manually. You must enter the correct SSID and authentication type and password in order to connect to the network. If both the credentials are correct, the Android phone will be able to connect to the network.

Wi-Fi Keeps Disconnecting Frequently

Reason
The most obvious reason for the problem may be with the Wi-Fi Sleep Policy which disconnects your Wi-Fi every time your Android goes to sleep to save your battery’s juice.
Solution
To manage Wi-Fi Sleep Policy, open Advance Wi-Fi settings on Android and tap the option Keep Wi-Fi on during sleep. Here, check the option Always  to enjoy an uninterrupted connectivity, but you will have to compensate it with your battery life.