Many older Wi-Fi devices do not have the 5GHz radios built in, so they must be connected via 2.4 GHz. If your device has the 5GHZ radios but you’re still not able to see the network, there is a chance it may be out of the 5GHz range. Higher frequency translates to shorter range. This means 5GHz frequencies do not penetrate solid objects as well as 2.4GHz which limits their reach inside homes.