jsxgraph - JSXGraph 线椭圆相交问题

Question

如codepen所示，当我拖动点a，b，c中的一个时，直线和椭圆的2个交点快速改变位置，这是一个错误吗？

let board = JXG.JSXGraph.initBoard('jxgbox', {axis: false,});
const showLabel = {
  withLabel: true,
  label: {
      anchorX: 'left', 
      anchorY: 'top',
      fontSize: 20,
  },
};

let a = board.create('point', [-2, 0], showLabel);
let b = board.create('point', [2, 0], showLabel);
let c = board.create('point', [0, 3], showLabel);

let ab = board.create('line', [a, b]);
let ellipse = board.create('ellipse', [a, b, c]);

let d = board.create('intersection', [ellipse, ab, 0], showLabel);
let e = board.create('intersection', [ab, ellipse, 1], showLabel);

https://codepen.io/ywlee/pen/MWmmKKg