Q: Call with iPhone failed OS-Xv10, iPhone6v9

The hand-off feature that allows me to select a phone number in a Safari window and then "Call from iPhone" launches the face-time app and attempts to make the call but never "hands off" to the phone and then comes back with a "Call Failed" message. I have followed all the instructions found here: Use Continuity to connect your iPhone, iPad, iPod touch, and Mac - Apple Support - to no avail. I have also followed the instructions found here: http://news.softpedia.com/news/Deep-Troubleshooting-for-Continuity-Issues-with-O S-X-Yosemite-463784.shtml but that was also no help. Here are the details of my configurations:

MacBook Air Early 2014, El Capitan 10.11.5

iPhone 6 at v9.3.2

Both devices have Blue Tooth and WiFi enabled, they are connected to the same wi-fi network and logged in to the same iCloud account, both devices are logged in to FaceTime, the iPhone preference has Wi-Fi Calling turned off and Calls on Other Devices turned on. The FaceTime settings on the iPhone does not have a "iPhone Cellular Calls" option that is referenced in a number of trouble shooting guides. I have logged out and back in to iCloud on both devices, and restarted both devices. If this feature was not so appealing to me I would have given up a long time ago, but I would really like this to work.