URLs to Stories are not Defining Default Args

[luisaugusto]

Describe the bug
When viewing a story that includes default arg values for the control, when one of the controls is updated, the URL of the story updates to reference the story with the modified control. The default args are not set in the URL however, and are set to !undefined instead, so if you send the link to someone, they will not see the story with the correct controls.

storybookerror.mov

To Reproduce

I can create a repo if needed, but this can be seen in all Storybook deployments, including the ones in the Encyclopedia. For example:

1. Navigate to The EU Icon Component (https://ec.europa.eu/component-library/playground/ec/?path=/story/components-icon--all)
2. Notice that the default args for the controls are:

• name: audio
• size: medium
• color: default
• transformation: none

3. Change the size control from medium to large. Notice that the URL changes to https://ec.europa.eu/component-library/playground/ec/?path=/story/components-icon--all&args=size:l
4. Refresh the page and notice that the URL changes to https://ec.europa.eu/component-library/playground/ec/?path=/story/components-icon--all&args=name:!undefined;size:!undefined;color:!undefined;transform:!undefined, and none of the args are set, therefore you cannot send a URL with custom controls set to someone else to view.

System
Occurring in my version of Storybook as well:

  System:
    OS: macOS 12.3.1
    CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  Binaries:
    Node: 16.14.2 - ~/.nvm/versions/node/v16.14.2/bin/node
    Yarn: 1.22.18 - ~/.nvm/versions/node/v16.14.2/bin/yarn
    npm: 8.7.0 - ~/.nvm/versions/node/v16.14.2/bin/npm
  Browsers:
    Chrome: 101.0.4951.64
    Firefox: 98.0.2
    Safari: 15.4
  npmPackages:
    @storybook/addon-a11y: ^6.4.19 => 6.4.22 
    @storybook/addon-actions: ^6.4.19 => 6.4.22 
    @storybook/addon-docs: ^6.4.19 => 6.4.22 
    @storybook/addon-essentials: ^6.4.19 => 6.4.22 
    @storybook/addon-links: ^6.4.19 => 6.4.22 
    @storybook/builder-webpack5: ^6.4.19 => 6.4.22 
    @storybook/manager-webpack5: ^6.4.19 => 6.4.22 
    @storybook/preset-scss: ^1.0.3 => 1.0.3 
    @storybook/react: ^6.4.19 => 6.4.22 
    @storybook/testing-react: ^1.2.3 => 1.2.4 

Additional context
N/A

[shilman]

Please try upgrading to 6.5. Is it fixed in the latest release?

npx sb upgrade

[luisaugusto]

Ohhh it's fixed in 6.5, closing this issue.