Copying blocks does not generate new UUIDs, causing cross-document block ID duplication

[bwcroft]

Describe the Bug

When copying content from a block field and pasting it into a new entry, the system does not generate new UUIDs for the pasted block entries. Instead, the blocks retain their original UUIDs from the source document.

Because block UUIDs are duplicated across documents, the affected entries cannot be published. This makes copying block-based content between entries unreliable and blocks common content reuse workflows.

Link to the code that reproduces this issue

https://bitbucket.org/clearlinkit/payloadcms-issues/src/master/src/issues/block-duplicate-uuid/BlockDuplicateUUID.ts

Reproduction Steps

block-douplicate-uuid-demo.mov

Which area(s) are affected?

area: ui

Environment Info

Binaries:
  Node: 20.11.0
  npm: 10.2.4
  Yarn: 1.22.22
  pnpm: 10.6.4
Relevant Packages:
  payload: 3.70.0
  next: 15.4.10
  @payloadcms/db-postgres: 3.70.0
  @payloadcms/drizzle: 3.70.0
  @payloadcms/graphql: 3.70.0
  @payloadcms/next/utilities: 3.70.0
  @payloadcms/richtext-lexical: 3.70.0
  @payloadcms/translations: 3.70.0
  @payloadcms/ui/shared: 3.70.0
  react: 19.2.1
  react-dom: 19.2.1
Operating System:
  Platform: darwin
  Arch: arm64

[github-actions]

Please add a reproduction in order for us to be able to investigate.

Depending on the quality of reproduction steps, this issue may be closed if no reproduction is provided.

Why was this issue marked with the invalid-reproduction label?

To be able to investigate, we need access to a reproduction to identify what triggered the issue. We prefer a link to a public GitHub repository created with create-payload-app@latest -t blank or a forked/branched version of this repository with tests added (more info in the reproduction-guide).

To make sure the issue is resolved as quickly as possible, please make sure that the reproduction is as minimal as possible. This means that you should remove unnecessary code, files, and dependencies that do not contribute to the issue. Ensure your reproduction does not depend on secrets, 3rd party registries, private dependencies, or any other data that cannot be made public. Avoid a reproduction including a whole monorepo (unless relevant to the issue). The easier it is to reproduce the issue, the quicker we can help.

Please test your reproduction against the latest version of Payload to make sure your issue has not already been fixed.

I added a link, why was it still marked?

Ensure the link is pointing to a codebase that is accessible (e.g. not a private repository). "example.com", "n/a", "will add later", etc. are not acceptable links -- we need to see a public codebase. See the above section for accepted links.

Useful Resources

• Reproduction Guide
• Contributing to Payload

[swheeler7]

Running into the same issue

[LouisTrinczek]

Running into the same issue, it was very frustrating to debug the cause of this