It is very easy to replicate. You can make sure of the sample line chart at https://www.htmlelements.com/vue/demos/chart/line-series/

Just edit the smart chart element there by ‘right-click and inspect’ and then add a style ‘zoom: 0.8’ to it. The chart will become smaller size. And, you can see that the tooltip is not showing the correct series my cursor is pointing at and the tooltip position is not aligned with my pointer.