How to stop wifi disconnection when eth0 link becomes ready?
Solution 1:
You'll want to go in the connection's configuration settings, under the IPv4 Settings tab, click the Routes button, and check the checkbox marked "Use this connection only for the resouces on its network".
What this does is tell NetworkManager to not use that connection as a default route. However, you'll need to edit it again to remove that option if you want to use wired as a connection for the internet (or create a separate connection just for changing old wifi settings).
