Hi peterfromtn,
If you are having trouble making a call from your Mac using FaceTime, take a look at the resource below for some troubleshooting steps. You may need to turn off some of the Continuity settings, restart your Mac, and then enable them again to reset everything.
Use Continuity to connect your iPhone, iPad, iPod touch, and Mac
Turn off Handoff
If you want to turn off Handoff on your iPhone, iPad, or iPod touch, go to Settings > General > Handoff & Suggested Apps. Then turn off Handoff.
On your Mac, go to System Preferences > General. Then uncheck the Allow Handoff setting.
Set up iPhone Cellular Calls
- You need iOS 8 or later on your iOS devices and OS X Yosemite or later on your Mac.
- Check that you're signed in to iCloud with the same Apple ID on all of your devices.
- Use the same Wi-Fi network on all of your devices.
- Sign in to FaceTime with the same Apple ID on all of your devices. This means any device that shares your Apple ID will get your phone calls.
Make a call or answer a call
- To make a phone call on your Mac, find a contact's phone number in Contacts, Calendar, or Safari. Hover over the number and click the phone icon that appears to the right of the number.
- To make a phone call on your iPad or iPod touch, tap or click a phone number in Contacts, Calendar, or Safari.
- On your iPad or iPod touch, you can slide to answer a phone call. On your Mac, a notification appears when someone calls your iPhone. Then you can answer the call, send it to voicemail, or send the caller a message, right from your Mac.
Turn off iPhone Cellular Calls
To turn off iPhone cellular calls on your iPad or iPod touch, go to Settings > FaceTime and turn off iPhone Cellular Calls.
On your Mac, open the FaceTime app and go to FaceTime > Preferences. Click Settings and deselect the iPhone Cellular Calls option.
Take care,