Arduino seen as HID device with external power?

Hi everyone,
I'm working at a project that uses an Arduino Micro and a PowerBoost 500 charger in order to provide the external power. I've connected the PowerBoost output to the 5v pin of the Arduino.
At the moment the serial communication works fine, but I cannot see the Micro as HID device. Is there a way to do that with external power supply? Basically I need to see the Arduino as a HID joystick (using ArduinoJoystickLibrary) without the usage of a usb cable.
Thank you

I suspect that you do not start HID functionality in your sketch. But you don't show the code, so it's just a suspicion.

And the question is:

If you don't want to use a USB cable, why do you need HID functionality? And how will a USB host be able to communicate?