I'm having the same problem, it happens whether I'm connected through wireless or wired connection.
Running with Win7 64-bit, Lenovo T440s
- Dual Band Wireless-AC7260, Driver Version 17.0.5.8
- Ethernet Connection I218-LM, Driver Version 12.11.96.1
As a workaround I disable/enable the network adapters.
If there's any additional information/logs to provide I would be glad to assist.
Please keep us updated on driver releases.