React: Conditionally rendering causes scroll element to scroll to top

Describe the bug

When a 2nd conditionally rendered virtual list is rendered, the page automatically scrolls to the top

Your minimal, reproducible example

https://codesandbox.io/p/devbox/cranky-fermat-vzkmd3

Steps to reproduce

Scroll to bottom and click the Render More button. Once clicked the 2nd virtualized list will render and the page will scroll to the top

Expected behavior

When the 2nd virtualized list is rendered, the page should not scroll to the top.

How often does this bug happen?

Every time

Screenshots or Videos

https://github.com/user-attachments/assets/4309df5d-4e1c-4900-bf5a-aced7b66757a

Platform

• OS: macOS
• Browser: Chrome 137

tanstack-virtual version

3.13.12

TypeScript version

5.8.3

Additional context

No response

Terms & Code of Conduct

• I agree to follow this project's Code of Conduct
• I understand that if my bug cannot be reliable reproduced in a debuggable environment, it will probably not be fixed and this issue may even be closed.

Start with the linked CodeSandbox reproduction and inspect how the second virtualized list is rendered after clicking “Render More.” Compare the page scroll position before and after that render in the reported environment. Done means the second list renders without moving the page to the top, while the existing reproduction behavior remains intact.