If you are attempting to use Split Tunneling via macOS, you may encounter an issue with the Split Tunnel System Extension being automatically disabled by default, which will cause the feature not to work as expected. 

When the split tunnel extension is used for the first time in macOS, the OS pops up a one-time prompt indicating the user should allow the extension in system settings. This can sometimes be missed if the dialog is just closed, and not actioned at that time.

Here are the instructions on how to enable this feature if needed:

How To Enable Windscribe Split Tunnel Extension in macOS System Settings

1. Open System Settings (Command + Space, type "System Settings", press Enter).
2. In the left sidebar, select General.
3. Click Login Items & Extensions.
   
   
4. Scroll down to Extensions and click the info (ⓘ) button next to Network Extensions.
   
   
   
   
5. Locate Windscribe Split Tunnel Extension and toggle it ON.
   
   
   
   
6. If prompted, enter your macOS admin password or use Touch ID.
   
   
   
   
   
7. Restart Windscribe to apply changes.
   

 

Further Reading

What is Split Tunneling and how to use it
Why doesn't the Windscribe iOS app have Split Tunneling?