In my case, the network connectivity was functioning correctly, but I couldn't change any of the settings (network mgr interface wasn't working).

I previously stated that I performed the steps suggested in this post which fixed the issue for me, however this fix was only temporary. I turned the system on this morning and now the networking isn't functioning again. However this time it's quite the opposite situation of what it was for me the first time. The network manager app is working, but my network connection is not.

It seems as though the system decided to install the updates again... Hopefully disabling the automatic updates installation this time will keep it from happening again.