A quick update...
I called FordPass tech support. The agent I spoke with was able to confirm that my modem was properly installed according to the information on his side. He seemed reasonably convinced that the issue is on Ford's side. I asked him what I should and shouldn't do. Things I shouldn't do are, Resetting the Sync 3 system to factory settings and removing the vehicle and activating the vehicle. Given that I was able to activate the vehicle and view all of the features on the FordPass app, he said it was ok to log off and log on once in a while. I still haven't received a call from an advanced guide, I was told to expect a call "soon".