This pattern commonly points to a Windows networking stack problem or interference from VPN software or its network filter/adapter. Since the PC shows Connected, secured but traffic only works after the VPN is enabled, try these steps in order:
- If a third-party VPN app is installed, completely uninstall it first, then restart the PC.
- VPN software can keep filter drivers or adapters that interfere with normal internet access even when the VPN is off.
- If internet works normally after uninstalling it, reinstall the latest version only if needed.
- Use Network reset as the next step.
- Go to Start > Settings > Network & internet > Advanced network settings > Network reset.
- Select Reset now > Yes.
- Wait for the PC to restart.
- After the reset, test the connection before reinstalling the VPN.
Important:
- Network reset removes network adapters and resets their settings to default. VPN client software or virtual switches might need to be reinstalled or set up again.
- After the reset, Windows may set known networks to the Public profile.
If the issue started after a Windows update and the VPN itself also has trouble connecting, reinstalling or updating the VPN client is also a supported step.