Erratic signal - Galaxy S5

[Anonymous]

Hi there,

I have recently switched from Orange to o2 as I was entitled to get the 30% Open discount on a good plan with a brand new Galaxy S5 - All good I thought but the signal I am getting is just awful. 

The phone can sit in the exact same place without being used and go from 3 bars of H+ to saying 'No Service'. Right now its sat in front of me showing 2 bars of E but earlier in the exact same spot was showing 3 bars of H. The signal seems so erratic and the unforunate thing is that its showing E more often which renders my data useless.

The postcode checker shows full coverage in my area for 3G with no schduled maintenance. On Orange I got full H+ signal all the time around my area and place of work so switching to something which is inferior its quite frustrating especially when I'm told I'm meant to get great 3G reception.

Is there anything I can do to help situation?

[MI5]

KitKat is a version of the operating system and has nothing to do with the modem which controls the phone signal (for both wifi and mobile reception), so technically KK cannot screw up your signal.
However, the modem that is bundled with KK could, in theory, be poor, but that wouldn't explain issues across different OE's as they all use a different modems.