I also have the same problem but I have not modified in my system since I have bought it, I use the preloaded ROM in Redmi 1S.
This problem has occured after I moved to Dubai from Delhi with 3G services
I am trying to acess the 3G via Du telecom in dubai and Changed APN and proxy etc as suggested by the Du cust support.
My SIM works well with in other mobile phone for 3G services and can access all sites and in my Redmi 1S I can only access google search page, youtube and whatsapp only however the phone works flawlessly on Wi-Fi and the problem persists if I insert some other Du or Etislat 3G enabled SIM card even
Some body said Dubai telecoms do not support chinese phone but Lenevo and Huaweii phones work fine here....
I dont want to migrate from Xiaomi...I love the preloaded functions and it makes my life easy...
Can any body help me out of this trouble.