Severe packet loss ACP70USZ with 6.3M1 driver on Dell XPS15

[olive]

I have a Dell XPS 15 (L521X) connected with a Targus ACP70USZ docking station. I have installed the newest version of the Displaylink driver 6.3M1. I have problem on Ethernet connection. It seems it suffers severe packet loss. I cannot connect to other PCs. To diag, I try to ping other machines on the same network. I can occasionally ping to other PC, but for most of the time I get 'Request timed out'. If I connect the same cable to the network port of my laptop, with exactly the same network TCP/IP settings, I have no problem ping to other PCs.
I talked with Targus live chat representative. She advised me to check the network card (Targus Giga Ethernet) advanced property and try different 'Speed & Duplex' settings. However, there is no such setting under this NIC configuration. I can only see 'MAC Address', 'VLAN ID' and 'Wake on LAN'.