Might be related to https://bugzilla.redhat.com/show_bug.cgi?id=519208.  I filed that bug almost two months ago and there has been no motion on it whatsoever.  I've tried the same scenario again recently with similar results.

Personally, I've given up on NetworkManager until I see some sign that somebody is actively working on making it stable and fully supporting it.  If a user files a bug report about serious breakage like this and nothing has been done with it almost two months later, that seems to me like a pretty clear sign that the package is not ready for prime-time.

If NetworkManager is considered a F12 core feature, then the bug I filed should probably be an F12Blocker, but I didn't mark it as such because I don't know if it's a core feature.

  jik