HP Printer shuts down connection to USB share switch

I have a hp printer that is connected to mine and my collegues dell laptops via a 2 pc; 4 usb share switch, and after a document has been printed the usb connection is terminated. This is frustrating, since the port is used for our broadband modem and it means it just disconnects you from the internet at the same time.

I have been on the hp site and found a document that appeared to have the answer using the toolbox function to turn off the bidirectional communication on the hp printer, but the option was grayed out and I was unable to establish whether bidirection communication was active or not.

Has anyone come across this problem before?