Question about i-tec Dual DP USB-C Power Delivery 4k Dock

Hi to you It's been working fine for me for over 6 months. The only thing is that I can't use the LAN port. The laptop recognises that a cable is plugged in, but has no access to the Internet. If I connect the cable directly to the laptop with a USB adapter, I have internet access. Does anyone have any idea why I can't access the internet via the docking station? Many thanks for your help and greetings