Recently we’ve been reported that some users have issues with not working WiFi on Xiaomi Mi5S. This issue may appear after you’ve flashed Custom ROM on your phone for the first time. Here’s the solution that we’ve recently tested. Hope it will help you to restore WiFi connection on your device as well!
[Solution] Can’t connect to WiFi on Xiaomi Mi5S
For this method you’ll require to have superuser permission enabled on your phone. Will also work on Xiaomi Mi5 with Custom ROM.
The issue is result of a broken MAC-address, which shows in red color in engineering menu.
Install ADB driver on your PC.
Flash your MIUI smartphone.
Enable developer options.
Then go to “Developer options” and enable “USB-debugging”.
Go to the folder with ADB files and press “Shift” + Right Mouse button at empty space, then select “Open command window here”.
Type the following commands in terminal window:
mv wlan_bt wlan_bt_bak
mv wlan_mac.bin wlan_mac.bak
After this make the factory reset of your phone and use clean MIUI firmware.