Confirm you have the correct platform SDK tools
For Windows 10, had to manually download the latest platform SDK tools from Android as the version supplied through Visual Studio 2017 EMDK for Xamarin was not sufficient. Everything else except adb.exe devices
worked.
https://developer.android.com/studio/releases/platform-tools
After the platform tools were manually downloaded, device showed up regardless of USB configuration (charging, MTP, etc.)
Installing an emulator device at this stage is also helpful to see whether the problem is with adb or your physical device.
List of devices attached
12345D1234 device
emulator-5554 device