Then you'll need to be more detailed about the network connections.
Windows will always use the first network connection in that list that makes the resource accessible. So let’s say you have two network connections to the same router. If both those network connections are configure identically except they have unique IP addresses (same subnet, same gateway ip, same dns server(s)), then only the highest priority network connection is ever used. The other goes UNUSED. Conversely, if those two network connections represent different subnets, then it will choose the appropriate one.
I have no idea how your network connections are configured, or if it even involves the Internet. But based on what I described above, maybe it now makes sense. If not, then as I said, you’ll have to provide more details about how those network connection are configured, are they the same or different subnets, do they have the same/different/no gateways, etc.