DocPages not pulling through DocGen comments on export default components

[tommaton]

Describe the bug
When I have a component which has been exported as default eg.

const Button: React.FC<IButtonProps> = ({})

export default Button

Then none of the DocGen comments come are show in the DocsPage for the components.

But when they exported as a const

export const Button: React.FC<IButtonProps> = ({})

Expected behavior
I expect this it to still pull through the DocGen comments into the DocPage whether it be a export default or export const

System
Environment Info:

System:
OS: macOS 10.15.7
CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
Binaries:
Node: 12.18.3 - ~/.nvm/versions/node/v12.18.3/bin/node
Yarn: 1.22.5 - ~/.yvm/shim/yarn
npm: 6.14.6 - ~/.nvm/versions/node/v12.18.3/bin/npm
Browsers:
Chrome: 87.0.4280.67
Edge: 86.0.622.69
Firefox: 81.0
Safari: 14.0.1
npmPackages:
@storybook/addon-a11y: ^6.0.28 => 6.0.28
@storybook/addon-essentials: ^6.0.28 => 6.0.28
@storybook/addon-info: ^5.3.21 => 5.3.21
@storybook/addon-viewport: ^6.0.28 => 6.0.28
@storybook/addons: ^6.0.28 => 6.0.28
@storybook/preset-typescript: ^3.0.0 => 3.0.0
@storybook/react: ^6.0.28 => 6.0.28
@storybook/theming: ^6.0.28 => 6.0.28

Additional context
Using TypeScript and Yarn Workspaces

[shilman]

Closing this as a duplicate to #9556