On your MAC, go to system preferences, network, WIFI, advanced, and set the preferred order of your WIFI connections.

@ArcherC8 

 

I just tried this. Still 5GHz is not detected automatically (and not even listed in the wifi connections available) till I manually turn off and on the wifi in macbook.

@Kevin_Z I only have 1 laptop in my home, so I've only tested this with macbook. For android phones that I have, I do not see this problem. 

The firmware is up to date - I checked it on the http://tplinkwifi.net firmware section.

 

The problem is not of "connecting" to 5GHz, but if macbook is searching for wifi since before router has boot up, the 5GHz is not even listed in the wifi list. Once I restart laptop OR turn off and on wifi, it auto connects to 5GHz. So, forgetting 2.5GHz essentially means, it won't connect to anything. 

 

I've tried all band and all channels combinations. Nothing has worked so far. This is the only part where the configuration of my Archer C7 differs from that of my Tenda ac1200. Tenda has channel 149 available and it's set to that, while C7 only has channels till 48 and I've set it to that. Is it possible to get channel 149 by flashing a different firmware version? maybe that is my last resort. 

 

Edit: I have an ASUS Transformer T100 convertible windows laptop. It's kinda old, but 5GHz still works on it so I tried to replicate this issue there. It was almost the same. I had to turn off and on the wifi in windows wifi settings for the 5GHz to be detected. So, I guess the problem is only with connecting to laptops and not mobile devices?