The information you presented has been read. And I replied accordingly. Since there maybe an issue with USB and scanning, and this printer has Ethernet abilities which you said it has in your 3rd reply, it's recommended to set up the printer using the LAN port available on the printer and then set up the drivers and scanning software on each PC that should be able to connect to the IP address of the printer. This should resolve the scan connection problem. Please refer to the printers Mfr support site and help to set this up.
Good luck.