Element UI version

2.13.2

OS/Browsers version

all

Vue version

2.6.11

Reproduction Link

https://codepen.io/pen/

Steps to reproduce

1. click "show msg" button
2. click "show 2 msgs" button
3. click "show 2 msgs async" button

What is Expected?

1. 1 MessageBox appears
2. 2 MessageBox appear in the function's calling order
3. 2 MessageBox appear in the function's calling order

What is actually happening?

1. 1 MessageBox appears
2. only the last MessageBox appears
3. 2 MessageBox appear in the function's calling order

As the reproducting codepen shows, when calling this.$msgbox multi time synchronously by clicking "show 2 msgs" button, it only shows the last one.
While when calling it synchronously with setTimeout , all the MessageBox will show in order.