Mesh Speeds: Slow when used with existing router
I have two mesh points that I have connected to my existing network (not using the Amplifi Router, it's an AT&T gateway). I have it set to use 5ghz to connect to the AT&T gateway, but clients are only connecting to it on 2.4ghz, and thus are very slow. When I turn on the additional SSID and set it to 5ghz, it's not even showing up as an available SSID. The gateway is 20 feet away in a closet, and clients can easily connect to the gateway on 5ghz. The connections strength shows as 100%.
So what's the problem? Why is the mesh point completely ignoring 5ghz, even when I set it to only use 5ghz? I have given up on trying to get the Amplifi router to work with this gateway, so I'm trying to get some sort of use out of this equipment that I paid so much money for, but now I can't even get the mesh points to use 5ghz.