[Bug Report] 级联选择器，开启 multiple 多选，lazy 懒加载 ，checkStrictly 时，数据回填，在级联面板中鼠标移动到选中节点（非叶子节点）时会清除已选数据

[limoning]

Element UI version

2.13.1

OS/Browsers version

macOS Catalina 10.15.4

Vue version

2.6.10

Reproduction Link

https://codepen.io/limoning/pen/mdeKGrx

Steps to reproduce

1.打开连接地址 2.点击级联选择器 3.鼠标悬浮到打开的级联面板中的 非叶子节点 ！！ 的选中值 4.效果是移除了选中状态

What is Expected?

在开启 multiple 多选，lazy 懒加载 ，checkStrictly 时 选中非叶子节点 鼠标悬浮在级联面板选中节点时不应该移除选中值

What is actually happening?

在开启 multiple 多选，lazy 懒加载 ，checkStrictly 时 选中非叶子节点 鼠标悬浮在级联面板选中节点时移除了选中值

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[905868332]

我也遇到了 难搞