Calling a method or property of another component using ref in one component raises an error when run build script, But running dev Script is normal

[jzfai]

Describe the bug

Reproduction

yarn create vite
cd vite-project
yarn
add Children.vue component to HelloWord.vue
call Children func thought ref in HelloWord.vue
run build script

System Info

{
  "name": "vite-project",
  "version": "0.0.0",
  "scripts": {
    "dev": "vite",
    "build": "vite build",
    "serve": "vite preview",
      "preview:build": "yarn run build && vite preview "
  },
  "dependencies": {
    "vue": "^3.2.11"
  },
  "devDependencies": {
    "@vitejs/plugin-vue": "^1.6.1",
    "@vue/compiler-sfc": "^3.2.11",
    "vite": "^2.5.6"
  }
}

Used Package Manager

yarn

Logs

vendor.df413e7c.js:1 TypeError: Cannot read property 'childrenFunc' of undefined
    at a (index.ea811d73.js:1)
    at go (vendor.df413e7c.js:1)
    at mo (vendor.df413e7c.js:1)
    at HTMLDivElement.n (vendor.df413e7c.js:1)

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/vue-next instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[github-actions]

Hello @jzfai. Please provide a minimal reproduction using a GitHub repository or StackBlitz. Issues marked with need reproduction will be closed if they have no activity within 3 days.

[jzfai]

git clone https://github.com/jzfai/vite-project.git

yarn run preview:build
click the red title to test
and then look the console info
@sodatea

[sodatea]

Bug in @vue/compiler-core: vuejs/core#4546
Will be fixed by vuejs/core#4549

[sodatea]

Workaround: use const refChildren = ref(null) instead of let.