Phone number of iPhone not in reports

Hi all,
currently testing ZMM, with iPhone 4 (ios 6) and some Android 2 & 4 devices.
I am unable to "receive" the phone number of my iPhone in the user list dashboard, neither in any device reports.
Why ?
While the one from some Android device running in Android SDK send it !
While I am¨, also, sure the phone number is displayed when calling (I mean not hidden)

Thank you,
Regards,
pascal