Bubble chart browser glitch

In a bubble chart (browser Chrome/ Edge), when the mouse pointer hoovers on a bubble, the tooltips keep quickly flashing, until I slide over the bubble area a little.

I tryed to clean the browse cache, refreshing the page, changing browser (MS Edge) with no luck.

https://photos.app.goo.gl/iuYd6tYTr6DhbMxh9 

This happens only on bubble chart: every other chart has no problems for tooltips.