I have a Galaxy S4, updated to Kit Kat on April 25th. Since then my 4G service has been horrible, if I get it at all. I'm usually on 3g or 1x, only one bar, sometimes roaming or no service at all. Called tech support, had me pull the battery and SIM card. After that I went and got a new SIM card. I just did a factory reset, that didn't help either. It seems that the soft reset helps, but only temporarily. After a while I'm back to crappy reception again. Are there phone settings that I need to change (APN, network settings, etc.) that got messed up with the update? PLEASE help!