Pasting multiple blocks between pages can cause child blocks at the original location to disappear

@tiensonqin is already working on this.

Since Sep 17, 2026.

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- [x] I searched and no similar issues were found

### What Happened?

When copying and pasting multiple blocks between different pages, some of the existing child blocks at the **original location of the copied blocks** can disappear after pasting.

Importantly, the data is not lost when the blocks are copied. The copied data remains intact at the original location immediately after the copy operation. The data loss occurs **when the copied blocks are pasted**.

This seems to occur more frequently when copying and pasting between multiple windows, which is a common workflow for me. However, I have also confirmed that the issue can occur when navigating to another page within the same window and pasting there, as well as when pasting into a page opened in the sidebar.

The bug does not occur consistently every time, but it becomes much easier to reproduce when a larger number of blocks are selected. It occurs frequently enough to be a significant issue.

I have observed this issue in both the Stable and Nightly versions.

**Please test this thoroughly and multiple times, as the issue is intermittent and may not occur on the first attempt.**

### Reproduce the Bug

1. Open a page containing multiple blocks with child blocks.
2. Select and copy multiple blocks from the page.
3. Confirm that the original blocks and their child blocks are still intact after copying.
4. Navigate to another page, either:

* in another window,
* within the same window, or
* in a page opened in the sidebar.
5. Paste the copied blocks.
6. Return to the original location and check the blocks that were copied.
7. Some of the existing child blocks may have disappeared.

### Expected Behavior

Pasting copied blocks should not modify or remove any data from the original location.

The original blocks and all of their child blocks should remain intact after the paste operation.

### Screenshots

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### Files

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### Browser, Desktop or Mobile Platform Information

windows11

logseq 2.0.1
and
logseq2.0.1-alpha+nightly.20260907

### Additional Context

_No response_

### Are you willing to submit a PR? If you know how to fix the bug.

- [ ] I'm willing to submit a PR (Thank you!)