S6 cant see my 5 GHZ wireless network . Really could use some help

Hello,

So I'm facing this weird problem, my s6 cant see the 5 GHZ network. But can see and connect to the 2.4 GHZ network. I've used the 5 GHZ network with a xperia z. I've flashed stock firmware via odin and also tried custom roms. Same problem. Any solution ?