Angular: Cannot render same story more than once in docs

Describe the bug When we need to show a story more than once in the mdx docs then only the first one shows

To Reproduce

ng g new sb-ivy
cd sb-ivy
npx sb@next init 

Remove the default export from Button.stories.ts

Add an mdx page to the button story

<Meta title="Example/Button"
  component={ButtonComponent}
/>

<Canvas>
  <Story story={stories.Primary}/>
</Canvas>

<Canvas>
  <Story id="example-button--primary" />
</Canvas>

npm run storybook

Click the Docs tab and notice the second Story is not rendered.

System Angular 12.0.2

System: OS: macOS 11.4 CPU: (12) x64 Intel® Core™ i7-9750H CPU @ 2.60GHz Binaries: Node: 14.15.5 - ~/.nvm/versions/node/v14.15.5/bin/node Yarn: 1.22.10 - ~/.nvm/versions/node/v14.15.5/bin/yarn npm: 6.14.11 - ~/.nvm/versions/node/v14.15.5/bin/npm Browsers: Chrome: 91.0.4472.77 Edge: 90.0.818.66 Firefox: 88.0.1 Safari: 14.1.1 npmPackages: @storybook/addon-actions: 6.3.0-beta.17 => 6.3.0-beta.17 @storybook/addon-essentials: 6.3.0-beta.17 => 6.3.0-beta.17 @storybook/addon-links: 6.3.0-beta.17 => 6.3.0-beta.17 @storybook/angular: 6.3.0-beta.17 => 6.3.0-beta.17 @storybook/builder-webpack5: 6.3.0-beta.17 => 6.3.0-beta.17 @storybook/manager-webpack5: 6.3.0-beta.17 => 6.3.0-beta.17

Additional context Add any other context about the problem here.

[shilman]

cc @IgorSzyporyn ☝️ another unique ID use case. @ThibaudAV we were discussing https://www.npmjs.com/package/nanoid

[shilman]

Yowza!! I just released https://github.com/storybookjs/storybook/releases/tag/v6.4.0-alpha.13 containing PR #15501 that references this issue. Upgrade today to the @next NPM tag to try it out!

npx sb upgrade --prerelease