Hi Christophe and Eswaran,
I just discussed this problem with Denis on IRC. Denis is quite sure the modem is broken.
To fix this, we need to add a quirk to the device driver in oFono code base which disables
the IP configuration reporting.
With this ConnMan will use DHCP in those cases.
Could you send me the exact modem description you are using? So that we can write quirk?
I am using TELIT 910 EUG Modem.