Does anybody know how to disable connman?
You can also configure connman to ignore a specific interface.
I had to do exactly the same (static IP for eth0) and could do so by
configuring it in /etc/network/interfaces AND
by modifying (adding) a line in /etc/connman/main.conf:
NetworkinterfaceBlacklist=eth0,SoftAp0,usb0,usb1I never did figure out how to disable it, so I ended up just deleting it:
sudo apt remove connman
Now my conventional, static IP configurations (in /etc/network/interfaces) are working fine.