1) In the "system Management" app in the “Autorun manager” disable all unused/rarely used apps.

2) In Settings -> WLAN -> Advanced disable the item "Scanning always available". (Disable this item, only if you are not need to check permanent location)

3) If in location is a bad connection 4G or 3G (constantly switches from 4G to 3G, 3G to 2G, then in Settings -> More -> Mobile networks -> network type to choose the type of network, which caught stable signal(3+ points).

4) It is not recommended to use third-party applications running with power saver mode-tracking applications. They can work constantly in the background and prevent the phone to go into sleep mode.

5) Check the errors in the sync accounts. Go to Settings -> Accounts, choose an account and then check if there is any synchronization errors. If there are errors, then try to sync the account manually.

6) It is not recommended to use a third party chargers for your phone, if for whatever reason you need it, just make sure that the settings were similar to the parameters of the original charge.

You can restart the router first. If the phone still fails to scan the hotspot, perform the following steps:

1. Check whether the router hides the SSID. For details about configuration on the router, see the router User Guide.

2. Detect the frequency and channels set on the router. And please change the channel to improve the signal strength.

3. Check whether the frequency of the router is set to 5 GHz. If yes, set the frequency of the router to 2.4 GHz (only for the phones supporting 2.4 GHz frequency).

4. If the preceding solutions don't work, use another phone to check whether hotspots can be scanned on that phone. If yes, take your phone to an authorized TP-Link service center and check the hardware.