Repository: storybook
Issue: MDX Docs' StorybookJS Default Theme Not Working After Upgrades to Storybook v7.0.0-alpha.34 with ReactJS v18.2.0 + NextJS v12.3.1
Labels: bug,needs triage

**Describe the bug**
I had a `partially-working` copy (Ref: https://github.com/storybookjs/storybook/issues/18383), after downgrading some `@mdx-js` libraries to a previous version `1.6.22` as follows:
```

"@mdx-js/preact": "^1.6.22",
"@mdx-js/react": "^1.6.22",

```

However, as my work build has currently progressed forward into a `monorepo` build using [`lerna`](https://lerna.js.org/) + [`pnpm`](https://pnpm.io/), I had to migrate forward to the latest versions of the `@mdx-js` libraries to enable some cross-libraries' functions.

Tentatively, I have managed to somehow "_fixed_" most of the "constantly-breaking" issues, but the main issue that I can't seem to fix is still **having the default StorybookJS theme being properly displayed**, and the UI issues I'm facing right now are similar to the ones I have previously reported [#18383](https://github.com/storybookjs/storybook/issues/18383#issuecomment-1159846202).


**To Reproduce**
[This is a work-related build, thus I will not be able to showcase all the info]

Please bear in mind that this issue relates to a `monorepo` build just to clear any potential confusion in the file structure.

**The key point to also note is that this build is running on `MDX2`.**

These are the main related dependencies I'm using:
```

// modules/docs/package.json (_This is a documentation module within a monorepo_)
...
"dependencies": {
    ...
    "@mdx-js/loader": "^2.1.3",
    "@mdx-js/mdx": "2.1.3",
    "@mdx-js/preact": "2.1.3",
    "@mdx-js/react": "2.1.3",
    "@storybook/addon-actions": "7.0.0-alpha.34",
    "@storybook/addon-docs": "7.0.0-alpha.34",
    "@storybook/addon-essentials": "7.0.0-alpha.34",
    "@storybook/addon-interactions": "7.0.0-alpha.34",
    "@storybook/addon-links": "7.0.0-alpha.34",
    "@storybook/builder-webpack5": "7.0.0-alpha.34",
    "@storybook/cli": "7.0.0-alpha.34",
    "@storybook/manager-webpack5": "6.5.12",
    "@storybook/react-webpack5": "7.0.0-alpha.34",
    "react": "18.2.0",
    "react-dom": "^18.2.0",
    "storybook": "^6.5.12",
    ...
  },
  "devDependencies": {
    ...
    "@storybook/addon-actions": "7.0.0-alpha.34",
    "@storybook/addon-links": "7.0.0-alpha.34",
    "@storybook/addon-postcss": "2.0.0",
    "@storybook/mdx2-csf": "^0.0.3",
    "@storybook/react": "6.5.12",
    "@storybook/testing-library": "^0.0.13",
    "@storybook/ui": "6.5.12",
    ...
    "next": "12.3.1",
    "preact": "^10.11.0",
    "storybook-addon-next": "1.6.9",
    ...
  },


```


**System**
Please paste the results of `npx sb@next info` here.

```

Environment Info:

  System:
    OS: macOS 12.5.1
    CPU: (8) arm64 Apple M1
  Binaries:
    Node: 16.15.0 - /usr/local/bin/node
    Yarn: 1.22.19 - /opt/homebrew/bin/yarn
    npm: 8.5.5 - /usr/local/bin/npm
  Browsers:
    Chrome: 105.0.5195.125
    Firefox: 100.0.2
    Safari: 16.0
  npmPackages:
    @storybook/addon-actions: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/addon-docs: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/addon-essentials: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/addon-interactions: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/addon-links: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/addon-postcss: 2.0.0 => 2.0.0 
    @storybook/builder-webpack5: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/cli: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/manager-webpack5: 6.5.12 => 6.5.12 
    @storybook/mdx2-csf: ^0.0.3 => 0.0.3 
    @storybook/react: 6.5.12 => 6.5.12 
    @storybook/react-webpack5: 7.0.0-alpha.34 => 7.0.0-alpha.34 
    @storybook/testing-library: ^0.0.13 => 0.0.13 
    @storybook/ui: 6.5.12 => 6.5.12 

```

**Additional context**
- TL;DR: **Running the `npm run storybook` command works, but the default theme is just not loading.**
- Due to the upgrade to `Storybook v7.0.0-alpha.34`, the new `npm run storybook` script command is now `sb dev` instead of the previous `start-storybook` ([Ref link of migration to v7.0](https://github.com/storybookjs/storybook/blob/next/MIGRATION.md#from-version-65x-to-700)).
- Sometimes, the dev command doesn't work all the time and randomly throws out a various series of different types of errors from time-to-time like:
- **[a] `WARN Force closed manager build`:**
```

/node_modules/.pnpm/webpack@5.74.0/node_modules/webpack/lib/NormalModule.js:758
                                const error = new ModuleBuildError(err, {
                                              ^

ModuleBuildError: Module build failed (from ../../node_modules/.pnpm/babel-loader@8.2.5_wfdvla2jorjoj23kkavho2upde/node_modules/babel-loader/lib/index.js):
/node_modules/.pnpm/@babel+core@7.19.3/node_modules/@babel/core/lib/config/config-descriptors.js:224
      throw new Error([`Duplicate plugin/preset detected.`, `If you'd like to use two separate instances of a plugin,`, `they need separate names, e.g.`, ``, `  plugins: [`, `    ['some-plugin', {}],`, `    ['some-plugin', {}, 'some unique name'],`, `  ]`, ``, `Duplicates detected are:`, `${JSON.stringify(conflicts, null, 2)}`].join("\n"));
            ^

Error: Duplicate plugin/preset detected.
If you'd like to use two separate instances of a plugin,
they need separate names, e.g.

  plugins: [
    ['some-plugin', {}],
    ['some-plugin', {}, 'some unique name'],
  ]

Duplicates detected are:
[
  {
    "alias": "/node_modules/.pnpm/babel-plugin-add-react-displayname@0.0.5/node_modules/babel-plugin-add-react-displayname/index.js",
    "dirname": "/modules/docs",
    "ownPass": false,
    "file": {
      "request": "/node_modules/.pnpm/babel-plugin-add-react-displayname@0.0.5/node_modules/babel-plugin-add-react-displayname/index.js",
      "resolved": "/node_modules/.pnpm/babel-plugin-add-react-displayname@0.0.5/node_modules/babel-plugin-add-react-displayname/index.js"
    }
  },
  {
    "alias": "/node_modules/.pnpm/babel-plugin-add-react-displayname@0.0.5/node_modules/babel-plugin-add-react-displayname/index.js",
    "dirname": "/modules/docs",
    "ownPass": false,
    "file": {
      "request": "/node_modules/.pnpm/babel-plugin-add-react-displayname@0.0.5/node_modules/babel-plugin-add-react-displayname/index.js",
      "resolved": "/node_modules/.pnpm/babel-plugin-add-react-displayname@0.0.5/node_modules/babel-plugin-add-react-displayname/index.js"
    }
  }
]

```
- [b] Endless Cycles of `WARN   Failed to load preset`


I hope the above will help provide some context on the issue I'm facing, though I do understand that due to the `alpha` release, there will still be a lot of issues to iron out before it becomes stable. 

Hope to seek some guidance on the above. 

Thank you!