3 beeps and disconnect on outgoing calls

I figured it out. My phone, mysteriously went back on airplane mode. It's been a week since I've returned and I did turn it off when we landed. It was working fine until yesterday. My adult daughter, who also has an iPhone, figured it out. I had an update waiting to happen, so we did that. Restarted the phone and went to settings and put it on airplane mode and then took it off. That did it. My settings for bluetooth were off in my car, but that was easy to fix.

See my reply above. It wasn't a network thing. It was a fluke. After being off of airplane mode for a week, it mysteriously went back on! All set now. Thanks.