Flash a new kernel, it's a common problem also check your radio you may have the wrong one and yes wifi binaries are region sensitive for broadcom chipset also download wifi manager and set your channel above 12 and 5ghz to your region
P. S. This problem even exist in notebooks
And windows users have bad time when it happens
I have the same problem from time to time. Solution is:
1. Turn Off Wi-Fi.
2. Use Root Explorer.
3. Go to data/misc/dhcp.
4. Delete the only file on this directory.
5. Now you will connect to Wi-Fi.