[Bug Report] I18n issue with Select when using [email protected]

[nzh63]

Element UI version

2.12.0

OS/Browsers version

Windows10 1903 / Chrome 77.0.3865.90

Vue version

2.6.10

Reproduction Link

https://codepen.io/nzh63/pen/rNBPNpP

Steps to reproduce

1. Use [email protected] and impoet the language files.
2. Click the "Swich Language" button.
3. No matter how many times the button I have clicked, the placeholder of el-select dose not change to Endilsh.

What is Expected?

The placeholder of el-select should change between "Select" and "请选择" when I change Vue.config.lang, just like el-date-picker and message-box's behaviour.

What is actually happening?

The language of el-select's placeholder does change even once, while el-date-picker and message-box change between Chinese and English as expect.

(The button of message box can change between "OK" and "确定", but of el-select is always Chinese)

[stale]

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.