UPDATE: I went and played with the Menu myself and when connected to a VPN I can see a **disconnect from VPN… ** option initially however when I disconnect from the VPN the option for it is completely gone and there is not reconnect option.
Example of how easy it is to disconnect and change VPN’s with OpenVPN below.
I suggest you use OpenVPN or another VPN management application to properly support your workflow.
PREVIOUS: Worst case scenario, your preference’s might be outdated or corrupted from the migration assistant. This could be any Wireless / WiFi / VPN plist file located in the System or User library directory.
I suggest rebooting and if that does work, redo your configurations. You can remake your vpn configurations without a reboot.