We are having the identical issue with this model NIC which is integrated in a HP Probook 650 G2.
It happens randomly and we cannot seem to recreate the problem on demand.
The link light on the onboard NIC "bounces" from up to down every 1-3 seconds. The switch it is connected to also indicated the link state is cycling between up/down every 1-3 seconds.
We ordered a bulk number of these laptops recently and are attempting to deploy them to our users however they are causing this issue randomly.
We have performed extensive troubleshooting without success. We have used the updated drivers directly from Intel as well as the driver from HP with the same results.