Volumio USB on MBP

Made a USB according to instructions on using image for PC, w/Etcher, flashed and checked ok. Boot to PC/Win10, and get msg that it will not Authenticate. I can see several different files, including one indicating Volumio, and EFI, but when I try to load them, they do not authenticate either. Machine will boot normally from here to log in screen, but of course the USB is not accessible (also shows 3 devices, E: F: G: which cannot be accessed). I switch the USB to my Mac-MBP OS High Sierra. I reboot the machine after i assign it to home WIFI settings, and select the EFI disk option.

The VOLUMIO screen appears, but there is no SSID visible-- checked on my carrier’s website. The Volumio App on iPhone 8 cannot find Volumio either.

How do I 1) get the USB device to broadcast the SSID?

  1. Get the device to then work?