[NU-1819] union copy fix

[Dzuming]

Describe your changes

https://github.com/user-attachments/assets/551a202b-493e-4326-9b0b-ccbd9c7d64fe

Checklist before merge

• [x] Related issue ID is placed at the beginning of PR title in [brackets] (can be GH issue or Nu Jira issue)
• [ ] Code is cleaned from temporary changes and commented out lines
• [ ] Parts of the code that are not easy to understand are documented in the code
• [ ] Changes are covered by automated tests
• [ ] Showcase in dev-application.conf added to demonstrate the feature
• [ ] Documentation added or updated
• [ ] Added entry in Changelog.md describing the change from the perspective of a public distribution user
• [ ] Added MigrationGuide.md entry in the appropriate subcategory if introducing a breaking change
• [ ] Verify that PR will be squashed during merge

[github-actions[bot]]

created: #7053 :warning: Be careful! Snapshot changes are not necessarily the cause of the error. Check the logs.