Stacked line chart data does not correspond to polylines

### Version
5.2.0

### Reproduction link
[https://echarts.apache.org/examples/zh/editor.html?c=area-stack](https://echarts.apache.org/examples/zh/editor.html?c=area-stack)

### Steps to reproduce
In the official example, the data cannot correspond to the broken line because the stack value is the same, which will cause numerical superposition. It will affect the discount display. I hope the official can modify the example

### What is expected?
Polylines correspond to data

### What is actually happening?
Polyline and data cannot correspond