Now edit "PreferredTechnologies = ethernet,wifi,cellular" to be "PreferredTechnologies = wifi,ethernet,cellular" and reboot, and the wifi connection will be the Internet connection when both are connected. If not, Ethernet becomes the internet routed connection when it's active.
I have the same problem. Is this solution still valid? I cannot find the 'connman_main.conf' file anywhere. Could you explain how to actually get to and edit the file? Can I access the file via samba and use a texteditor? (I don't have much experience with this, excuse me)
EDIT: Okay, figured it out, cp is a ssh command, you can edit the file that way. The solution still works! Cheers.