I have found the same issue and there is another separate discussion about this in the group (see thread here). I’d been thinking it was a problem with connman but after reading this thread, it seems that it is something more fundamental.
My findings:
- If I boot without LAN cable attached then LAN is never available even after plugging LAN in.
- If after booting with LAN attached, I unplug LAN for a few seconds then plug back in, the connection is re-established providing I add “Restart=on-failure” and “RestartSec=5” to the connman service control/launch file.
- If after booting with LAN attached, I unplug LAN for more than 5 seconds, the connman service restarts but then the connection can never be re-established without reboot.
Happy to try things if suggestions are offered 