Hello Geekzoners

I am have issues where someone tries to ring me and it ringing but my s7 edge doesn't ring or switch back from 4G.

i just end up with a txt saying I've missed a call or you have a voicemail.

Could this an issues with CSFB.

as if i move to either end of the house this issues goes away.

there full bars of signal but jumps around from band 40 to band 28 to band 3 

I am at a lost as every time  i have contacted skinny they blame my phone setting 

this has happen for sometime over many of different devices

s7 edge (spark branded)

note 5 (spark branded)

s5 (2degrees branded)

huawei y635

hayden