Cannot see 5GHz wifi

[cfrozendeath]

I have a TP-Link AC1200 (Archer C5) router with dual band: 2.4GHz on the rc2 SSID and 5GHz on the rc5 SSID.

I have tried:

-Turn off the 2.4GHZ

-Change the 5GHZ from ac to a/n/ac

-Multiple combinations of channel / channel width

-Connect through WPS push button

-Connect through WPF PIN

-Add the network manually

I'm sitting next to the router, and my Samsung Galaxy S6 and notebook can connect to both the 2.4GHz and 5GHz networks.

Phone info:

Model: H3123

Build: 50.1.A.5.59

Why cannot I connect to the 5GHz network?

[klaus0815]

To test switch to a single channel down below 48. deactivate the second channel in router. 

Some Hardwaremanufacturer want to save up royalty for the 5Ghz Wlan Channels above 48. Amazon Fire TV Stick or FireHD 8 as example could only connect to 5Ghz Wlan single channels from 36 till 48. 

IIt is important that you disable the second channel operation in the 5ghz network because if you set the channel to 48 the router usually chooses a 2 channel over 48 and your WLan is not visible to the XA2 again.