Nighthawk EX8000 not using 5 GHz WiFi backhaul not working

[SGranat]

I can find no information on Maximum Throughput using the 5 GHz band for backhaul. What is it? Do I set it up or is it automatic? The 2nd LED is unlit indicating that the extender is using the 2.4 GHz band, correct? How do I change this?  Thanks...

[plemans]

have you logged into the extender and looked at the status page? 

It shows backhaul connection speeds/links. 

You can take a screen snip and post that here. 

What router are you connecting it to? 

How far from the router is the extender? 

[Meribelman]

Hi. I have this problem too. I have been using the extender since April last year. It’s brilliant! A few days ago I lost the 5G backhaul. I have done a complete factory reset and tried a WPS set up. Regardless it is not setting up 5G backhaul. The router is an Asus RT AC 66U. Any advice most welcomed! Thanks in advance