Why does ConnMan report my MAC address as all zeros until I restart it?

Question

ConnMan (Connection-Manager) reports my ethernet adapter's MAC address as 00:00:00:00:00:00. However, if I restart the ConnMan service using

$ systemctl restart connman.service

it subsequently reports the MAC address as the actual address. Why does ConnMan report the ethernet adapter's MAC as zero until restarted?

The actual MAC address is passed from U-Boot to the kernel via kernel boot parameter ethaddr, and ifconfig always reports it rather than zeros.

I'm using the Angstrom distribution with ConnMan version 1.25.