USB Modem showing as tethering

Using Beryl 3000AX with software version 4.5.16. I have managed to connect Ethernet, Wireless and tethering to my iPhone. The last hurdle I tried was to connect an unlocked Vodaphone K5161z (with a Three sim card) into the USB modem port. The blue light is constantly flashing on the modem (Not connected) and it appears on the Beryl Admin panel as Tethered.
The modem works correctly if I plug it into my Macintosh Air. Any suggestions please.