This is the real issue cYrus had (we tracked it down via interactive chat):
The phone has obviously some race condition between plugging USB in and USB ready. Plugging in basically gives 2 events:
- Power connected event (start charging battery)
- USB connected event (enumerate devices etc.)
If the Host system asks for USB enumeration too quickly (before the power-connected event has settled probably), then that operation fails and the device stays invisible.
The workaround is to slowly insert the USB cable.
Reason: USB has 4 pins, the 2 outer ones are +/- and protrude longer than the inner 2 data pins. If inserted slowly, there's a time gap between the power-connected event and the data-connected event