I am unable to get 5GHz Wi-Fi working on my Home Hub 6 (Smart Hub). I have tried setting "separate bands" on and off. No matter what settings I use, using various apps, there is no indication that a 5GHz signal is being transmitted. Looking around the forum I can see that this appears to be a common problem. Taking into account everything that I've tried, I'm inclined to believe that the problem lies with the hub, possibly hardware. The firmware version is SG4B1000B540 dated March 2018. Can someone from BT assist?
if you have turmed off smart setup, split networks and selected channels manually and still your devices can't see the 5ghz network then phone customer services 150 and request a hub replacement
you could try factory reset first using recessed button on back and holding till lights flash about 20/30 secs