Mac not working without VPN

Then you have a file that was from the previous VPN that is still in your Launch folders/Extensions and it has not been removed properly. For some companies that is intentional to try and keep you using their product and other times it is because the uninstaller provided by the developer was not used.

We may be able to help locate which files are giving you trouble by posting the free EtreCheck report using the Additional Text option when posting. There is no personal information in the report.

How to use the Add Text Feature When Post… - Apple Community

That usually means your normal network routing or DNS got altered and never restored after a VPN install or removal. What’s happening is macOS is likely trying to send traffic through a virtual network interface that no longer works, so without the VPN tunnel it has no valid route out.

Don’t just look at Login Items, go to System Settings > Network and check if you still see a leftover VPN interface or a custom DNS server under your active Wi-Fi. Remove any manual DNS entries and set it back to automatic. Then open Terminal and run networksetup -listallnetworkservices to see if any ghost VPN services are still registered.

If you find one you don’t use, delete it from Network settings. Also check /Library/Preferences/SystemConfiguration/ for modified network configs only if you’re comfortable, because that’s where persistent routing changes live. In most cases, this isn’t Apple breaking anything, it’s a VPN profile that changed routing or DNS and didn’t clean up properly.