I have been using the D-link DWA-171 Wifi adapter for a while now but since yesterday the 5 GHz is no longer working, the adapter can only find the 2.5 GHz but 5 GHz is not showing at all. my brother has the same adapter when I connecting his one to my computer it works just fine, both 2.5 and 5 GHz. I have been resetting my router but unfortunately didn't help at all.
is anyone knows what would be the problem?