This article covers the throughput issue going drastically down with GVC software connected even though GVC is configured to use split tunneling. In few scenarios, the issue persists even after disconnecting the GVC, the throughput is not restored until the PC is rebooted.
The issue was identified by the Microsoft team on the specific build of the Windows 10 operating system related to the Receive Segment Coalescing (RSC) on the network adapter.
New patch files of Windows 10 have been released which take care of the issue hence either you may upgrade the windows operating system to the latest patch available or perform the following workaround:
Open an admin command prompt window:
Start > All Apps > Windows System -> Right-click "Command Prompt" > More > Run as administrator
Get your network adapter name:
Note your adapter's name
Get your network adapter "Receive segment coalescing" (Rsc) settings: