OnUnhover being called when it shouldn't

I'm not happy with the builtin tooltip for the polar chart, so I'm attempting to make my own, however I'm having issues with it hiding as soon as it should show, and form what I can tell this is because it's running OnUnhover on every redraw (while the cursor is anywhere near the chart)

I've attempted to set up a simple example here
https://codepen.io/tim-logan/pen/qBqOeMZ?editors=1010

Line 72/73 can be flipped in/out with comments to see the result either in console or directly on the plot.

I may just be doing something wrong, but it looks like a bug to me :)

从链接的 CodePen 复现开始，尤其关注第 72/73 行，并跟踪当光标停留在图表附近时，极坐标图重绘会在何时触发 OnUnhover。完成的标准是：自定义 tooltip 在重绘期间保持可见，并且只有当指针实际离开相关图表元素时才运行 OnUnhover。