I have used my Samsung Galaxy S4 as a wifi device for the past 3 months with android 4.2.2 and it worked perfectly fine as a wifi device with no sim card in until one day I decided to update it. So now the phone is running android 4.4.4 without a sim card and it wont let me switch the wifi on. What do I do, downgrade the phone back to 4.4.2?