Dropdown menu item group is not rendered

[anhthang]

trafficstars

• [x] I have searched the issues of this repository and believe that this is not a duplicate.

Version

4.1.0

Environment

@ant-design-vue/[email protected], [email protected], vue@latest

Reproduction link

https://stackblitz.com/edit/github-qersjw?file=src%2FApp.vue

Steps to reproduce

Just dropdown menu with item group

What is expected?

Dropdown menu item group is rendered

What is actually happening?

Dropdown menu item group is not rendered