Could you please report this bug upstream to the NetworkManager developers on the GNOME bug tracker? Sound like this issue is one that should be taken care of upstream.
To help with debugging, it would also be useful if you could attach full debug logs from NetworkManager after reproducing the issue, you can do this easily by starting NetworkManager with --log-level=debug.
Stéphane,
Could you please report this bug upstream to the NetworkManager developers on the GNOME bug tracker? Sound like this issue is one that should be taken care of upstream.
To help with debugging, it would also be useful if you could attach full debug logs from NetworkManager after reproducing the issue, you can do this easily by starting NetworkManager with --log-level=debug.