Version

3.0.4

Reproduction link

https://codesandbox.io/s/trusting-wu-n8cue?file=/src/App.vue:304-335

Steps to reproduce

app.mount(rootContainer)

What is expected?

getCurrentInstance all working

What is actually happening?

the second get null

I want to add some toast and then execute the logic,

You cannot create an app inside of the setup of another other app. It changes the current instance and that's why you see no instance after Toast()

You cannot create an app inside of the setup of another other app. It changes the current instance and that's why you see no instance after Toast()

Thanks~ But the documentation has no description, can it be added to the documentation? https://v3.vuejs.org/api/composition-api.html#getcurrentinstance