PRobably VMQ-problem ...
Have you checked this on your server?
https://support.microsoft.com/nl-be/help/2986895/virtual-machines-lose-network-connectivity-when-you-use-broadcom-netxtreme-1-gigabit-network-adapters
or this source: hxxp://www.aidanfinn.com/?p=19367
Greets
Tullius