At library, we have to use USB-adapter for wire connection, so the default network card is disabled.
My mint was working well with this,but after update to new version 19.1, its Network Manger come with a new function---randomly or stablely change MAC address automatically, as cloned MAC address. The internet connection is then stopped.
Since VPN kill switch function normally won't work with multiple network interfaces. The cloned MAC address is considered by VPN as more than 1 network interfaces, so it disabled the network.
Now even change Network-Manager to remain permanent as the original adapter's MAC address won't change this problem as well.
Does anyone have same problem? How to solve this problem please? Many thanks.