[Bug] Stacked area chart breaks when adding range area between two lines

### Version

5.6.0

### Link to Minimal Reproduction

https://echarts.apache.org/examples/en/editor.html?c=line-simple&code=MYewdgzgLgBFCm0AiBDKKYF4YG0BQMMA3jAB4BqKANgFwwCMAbAOwBMArAMz2sAMANDACelKvTr0Bw0azp8YAX34FiZURJYdurRoJHVxDVnplzWi5YRIVqGtl3qdj0g3QAcJ6rJgcLK6-oMmg6cHi5iEuyeVN6cvH5WarZB9twALGnRhvRh-jFybgmqNrQpWvTsUnnZmeGx5kr-SaVMqRW64YZ80bHsRQHJreWMztUaPXKM_c12w7miXaOmMKHTJbMOzLVjDACcEyucfgC6ANx4eCAADlAAluBYxCp3UFTwdEQqhAikUHQARABhAAWKAATlB_pYim8AObwMAAEw-XxgiLQKDoOH-1ShMBxMgAtLjBASvP9jtDvtc6HFoY1CKQAIKkW4QFGEb5CK7vfEAN2oAFd4FDUQBbW5gAHo9AAWUlos5MDFKFI0oxstViqKQhZbI5nKg3N5_wFVGF2oZMAg8DBt0QWNRnyVhDAKDFJpJqK5PIBVElIqpnJlmLgiCgqHQADoVVcABRx24IMUASiwAD5cEn4GKoyVBNnc9Vjimg4QIEIxQAjEClf7AW5g4BvbVK6AoYAAawBYJQYHhraKVm9MDdHoBeVYxIWg59Jv9YEDI5DdAQyAxMZQ8cTybTmEzOELedEBeTUcnMEJMCPxdLI_B8BQAGUjW8DS6YKAqCAwT3YVWUDjdh6EECpnFYeh9hgXgo04FNZyHTkK2rWsATAcAlw_dsux7PsByDK1hw_MdPRkBCjV9fEF0wl0VzDddo1jBNCz3A8j3za8z0nEsy2tSsazrBsmxbAjoUpPAFFOIA

### Steps to Reproduce

see Link to Minimal Reproduction

### Current Behavior

- With all three series enabled, the chart displays incorrectly
- When disabling `yVal2-yVal1` via legend, the remaining two lines display properly

### Expected Behavior

All three series should display together with `yVal2-yVal1` as a filled area between `yVal1` and `yVal2` lines

### Environment

```markdown
- OS: macOS Sequoia v15.5
- Browser: Chrome v137.0.7151.70
- Framework: none
```

### Any additional comments?

I'm trying to create a chart with Apache ECharts that displays two line series (`yVal1` and `yVal2`) and a range area (`yVal2-yVal1`) between them. However, when the range area is enabled, the chart behaves strangely. The lines become misaligned and the visualization breaks. When I disable the range area via legend, the remaining two lines display correctly.