Triangulation of thin ring contains gap

Hi, I', wondering whether this behaviour is valid. I triangulate a thin ring using the following meshing parameters
deflection (relative) = 0.5
angular_deflection = 0.6

As you can see in the attached screenshot, a gap appears in the ring. I would have expected that the triangulation is always preserving the topology of the shape?

Fabian Hachenberg's picture

Here's the geometry