ECharts: Statistics Graph has no Legend

[karwosts]

Checklist

• I have updated to the latest available Home Assistant version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.
• I have tried reproducing the issue in safe mode to rule out problems with unsupported custom resources.

Describe the issue you are experiencing

Statistics graph card is completely missing the legend. I see this message always repeated in the console anytime I load a statistics graph card, perhaps it is related:

ha-chart-base.ts:183 Carbon dioxide series not exists. Legend data should be same with series name or data name.
ha-chart-base.ts:183 Carbon monoxide series not exists. Legend data should be same with series name or data name.

Describe the behavior you expected

Legend

Steps to reproduce the issue

1. Have a statistics graph card
2. ???
3. No legend
   ...

What version of Home Assistant Core has the issue?

2025.2.dev

What was the last working version of Home Assistant Core?

No response

In which browser are you experiencing the issue?

No response

Which operating system are you using to run this browser?

No response

State of relevant entities

Problem-relevant frontend configuration

chart_type: bar
period: hour
type: statistics-graph
entities:
  - sensor.carbon_dioxide
  - sensor.carbon_monoxide
stat_types:
  - mean
  - min
  - max

Javascript errors shown in your browser console/inspector

Carbon dioxide series not exists. Legend data should be same with series name or data name.
eval @ LegendView.js:221
each @ util.js:205
LegendView.renderInner @ LegendView.js:139
LegendView.render @ LegendView.js:105
eval @ echarts.js:1581
each @ util.js:205
renderComponents @ echarts.js:1578
render @ echarts.js:1565
update @ echarts.js:1197
ECharts.setOption @ echarts.js:408
handleKeyUp @ ha-chart-base.ts:88

Additional information

No response