Dell Precision M6800 looses network connection on i217-LM

I got the new Precision M6800 as an service upgrade after my Precision M6600 failt totally.
Now using this one in my docking station gives me a really hard time on the i217 network.

The wired network connection is failing after a while (let's say aftet 1-2h) and the wifi kicks in.
This is really annoying bcos I don't have access to all my network drives going over the wifi.

I can't really figure out why this happens. Any diagnosis or unplugging&replugging the network
cable helped. Only thing which instantly helps is undocking and redocking the m6800 itself.

Does anyone else has this issue? I have this problem either using VMware switch option (so
the Hyper-V adds a virtual network card through which traffic goes) as well as without this one.

So it's not a problem of the Hyper-V layer of my virtual environment. It's - as a matter of fact - a
problem of the laptop. Or let's better say it's a problem of the dockingstation (as far as I can tell).