I have a chromecast with google tv that's connected to my living room tv. I CAN connect the device via 2.4 ghz but I cannot connect via 5.
The router in question is a Asus RT-AC86U with the latest firmware (the chromecast also has the latest firmware.) The chromecast see's the ssid but when I enter the credentials (and I know they work as I used it with my pixel phone and a old laptop) it won't connect.
I'm paraphrasing here but I get a messaging stating that the network doesn't exist OR when I try to connect it takes forever and errors out.
I did do a factory reset.
Also the router is next to the tv (less than a foot away.)
Ok ...I did some "googling" around and apparently others have this same issue. Apparently, you have to change the 5g frequency to something like 36. I did and it works!