Devices cannot connect to my shared Wi-Fi I have a Late-2016 MacBook Pro without Touch Bar.

When I create a shared Wi-Fi network through System Preferences -> Sharing (while I have my machine connected to ethernet via a USB-C adaptor), no device can connect.

The network is configured with WPA-2 personal security (just a password, though I have also tried with no security and end up with the same result).

When I try to connect with security enabled, my iPhone always says incorrect password (though I've confirmed the password is correct). When I try to connect without any security, my iPhone just says unable to connect. I have had colleagues try with their phones and computers with the same results.

Any recommendations?
Head to the Genius Bar and show them. If they deem it to be a hardware issue they may replace the defective board.