KeepAlive with keyed child and scoped style not working

[danyadev]

Version

3.0.0-beta.18

Reproduction link

https://github.com/danyadev/vue3-bug

Steps to reproduce

Double click on the button and look in DevTools

What is expected?

no changes

What is actually happening?

the text "Foo" disappeared and an error appeared in the console:

TypeError: Cannot read property 'subTree' of null (runtime-core.esm-bundler.js?5c40:208)
    at move (runtime-core.esm-bundler.js?5c40:3677)
    at Object.sharedContext.activate (runtime-core.esm-bundler.js?5c40:4330)
    at processComponent (runtime-core.esm-bundler.js?5c40:3196)
    at patch (runtime-core.esm-bundler.js?5c40:2857)
    at componentEffect (runtime-core.esm-bundler.js?5c40:3384)
    at Object.reactiveEffect [as update] (reactivity.esm-bundler.js?a1e9:42)
    at updateComponent (runtime-core.esm-bundler.js?5c40:3273)
    at processComponent (runtime-core.esm-bundler.js?5c40:3203)
    at patch (runtime-core.esm-bundler.js?5c40:2857)
    at patchBlockChildren (runtime-core.esm-bundler.js?5c40:3128)

[danyadev]

However, this is not the only problem with Keep-Alive. This is the second unplanned problem when trying to reproduce another bug:

(This is most likely due to the fact that there is no check for the lack of a deactivated hook)

In the near future, I hope I will argue this too. The difficulty may be that I use Keep-Alive with the beta version of the vue-router

Edit: Turns out it wasn't related to vue-router