Huawey E173 not recognized by RB2011-UAS-2hnd

Hello, I installed the Huawey E173 on a RB951-2hnd without any problem, just a plug and play. But the usb port of RB2011 don’t see it (but the green/blue led flashes). No usb ports in the port list, nothing. Any idea?
Thank you

unplug the modem from the board, remove the power from the board, power the modem back to the board and only then power on the board and check again.

Thank you very much,
now it’s running!
Kind regards,
Toni