How to add Geofence

I had initial trouble like netgelder described. Turns out I was click+holding mouse to draw, when I should have done click+release.

• Go to Settings -> Geofences; a map appears
• Click the Square (Polygon) or Line tool in top left of the page
• Click anywhere on the map and release
• Move mouse to somewhere else. A dotted line should appear, following the mouse.
• Click+release in more places to form an area
• Doubleclick to add a final geofence point and you will be prompted to Save

It's very slick once you know how to do it.

That's really helpful, but I'm still struggling to find how to create a circular geofence.
It used to be possible: I still have some, but I can't make new ones any more.