Must be a scammer- because it was stopped after one ring by my national robocall blocker.

Where do you find the to robo call blocker if I may ask? Thanks!

Where do you get a Robo Blocker?

There is a free call blocking service that is not available on every phone system.  The filter prevents me from posting it or the thread link here.  Think No    More     Robot.  Put a play on those words and you will find it.  As an alternative

Call Blocker
You need to buy a standalone call blocker, call blocking phone, use your carrier’s call blocker if they offer one, or download a free call blocking app for smart phones.  For conventional cell phones, assign the number a letter like “z” and make no ring.  You may also need to have your carrier increase the ring time to avoid having them leave a message on your voice mail.

No message left. Caller ID says, "DC, USA."