[Component] [date-picker] DateTimePicker组件-时间范围选择-默认开始、结束时间功能缺陷

[fanfan-Z]

Bug Type: Component

Environment

• Vue Version: 3.5.13
• Element Plus Version: 2.13.3
• Browser / OS: chrome
• Build Tool: Vite

Reproduction

Related Component

• DateTimePicker

Reproduction Link

Docs

Steps to reproduce

DateTimePicker组件使用datetimerange进行范围选择,选项default-time传入值，开始、结束日期选择同一天后，点击开始日期的时间选择面板，修改开始时间点后，结束日期的时间点会同步变为开始时间点

What is Expected?

修改开始时间点后
结束时间点不会自动修改

What is actually happening?

修改开始时间点后，结束日期的时间点会同步变为开始时间点

Additional comments

复现链接为组件库官方网址中的组件示例，因不清楚组件库网址中的vue版本、组件版本及构建工具，因此表单中填写值不一定准确
请以复现链接（组件库官方网址）中的为准

[keeplearning66]

Thank you for the feedback!
The reason is that the default-time prop is set with the start time being later than the end time. Therefore, when selecting the same day, the end time will also change when you click the start time. After adjusting default-time, it works fine. demo
As for why the end time changes synchronously when modifying the start time, it is to prevent the start time from being later than the end time. This issue is a duplicate of #21797.