Addon Docs: preview doesn’t change when switching between stories and not going back to canvas

[CodeByAlex]

Describe the bug
When switching between stories, if you never click back on the canvas the components in iframes on the docs page don’t change. The Markdown does change however.

To Reproduce
Steps to reproduce the behavior:

1. Follow the steps to setup docs for angular found here: https://medium.com/storybookjs/storybook-docspage-e185bc3622bf
2. Go to a story
3. Click on docs tab
4. View component preview
5. Go to different component story
6. See that the preview doesn’t change but the markdown does

Expected behavior
Docs preview should show the correct components based on the story

Screenshots
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Code snippets
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System:
Please paste the results of npx -p @storybook/cli@next sb info here.

Running angular 7 with latest version of addons ( will provide more info soon

Additional context
Add any other context about the problem here.

[shilman]

Repro'd on examples/vue-kitchen-sink. AFAICT it's only the first story, and it's only for iframe stories (i.e. non-react stories). Investigating.

[CodeByAlex]

I can confirm with @shilman that it is only the first story in angular as well.

[shilman]

Fixed in #7849

[shilman]

Yay!! I just released https://github.com/storybookjs/storybook/releases/tag/v5.2.0-beta.40 containing PR #7849 that references this issue. Upgrade today to try it out!

You can find this prerelease on the @next NPM tag.

Closing this issue. Please re-open if you think there's still more to do.