Demo: https://play.nativescript.org/?template=play-vue&id=liGhQ2

<Page>
  <StackLayout>
    <Button @tap="counter++">{{counter}}</Button>    
    
    <keep-alive>
      <CompButton v-if="isOdd" key="odd" label="Odd"></CompButton> 
      <CompButton v-else key="even" label="Even"></CompButton>
    </keep-alive>
  </StackLayout>
</Page>

<CompButton> is just a simple wrapper of <Button>. This template is almost everything of the app (except a definition of data counter).

The counter starts from 0. When counter <= 2 everything goes fine. But after that, no <CompButton> will be rendered in the view. Everything else functions well, and no <CompButton> is destroyed (means the keep-alive is working).

If replace the custom component with a bare <Button>, no more issues.