Tooltips missing for points on StackedAreaChart

[obambrough]

I am submitting a...

• Feature request
• Design defect
• Source code defect
• Demo/documentation defect
• Other

charts version:

charts: 0.34.9

Issue description

StackedAreaChart doesn't show tooltip for point on any dataset other than the first dataset (e.g. only the datapoint lowest on the y-axis has a tooltip shown when the mouse is hovering over the point.)

Steps to produce the issue

This is present on any StackedAreaChart

Current behavior

When you hover over a graph point it only shows the tooltip for the bottom most point on the y-axis.

Expected behavior

The individual tooltip should appear when hovering over any graph point.

Screenshot or recording

The behaviour can be seen on the Carbon Charts storybook: https://carbon-design-system.github.io/carbon-charts/?path=/story/area--stacked-area-time-series

Short recording showing only the lowest datapoint shows a tooltip
Missing tooltips.mov.zip

[hlyang397]

I think #764 may fix this problem.