Power source to programming vesc

At the end I use a regulated power supply either at 21.2V (you can choose any value I guess) and 4A limited current.

Question: When I power the VESC from external source and operate it, can I leave the st-link debugger USB dongle connected to the VESC (but disconnected from the PC)?

I noticed that the VESC makes the little led on the usb blinking and I was wondering if that may be a problem.

I have just realized myself that the VESC does not start with the debugger plugged in. Even with the 3.3V and GND pin disconnected