[Bug] [v2] Visible content position is not maintained when items are added and removed at the same time

[jmysliv]

Current behavior

I have a function that removes one item and adds new ones when the user reaches the start of the list (backward pagination). However, instead of maintaining a visible content position, it scrolls automatically to the top.

Simulator.Screen.Recording.-.iPhone.16.Plus.-.2025-05-20.at.16.29.34.mp4

Expected behavior

It should keep the current scroll position.

To Reproduce

https://github.com/jmysliv/rn-playground/tree/%40jmysliv/flash-list

Platform:

• iOS
• Android

Environment

2.0.0-alpha.11

[naqvitalha]

That's a good edge case. I'll fix it in the next release.

[naqvitalha]

I looked at your sample. It would be great to have a sample where data isn't tied to the component. With every render and index change, the size of the component can change. It might be a real use case however, it makes debugging a single issue very difficult. Let me know if you can provide a simpler one otherwise I'll come to this when I have some more time.

[jmysliv]

@naqvitalha got it. Here I pushed a simpler example, with data extracted out of the component: https://github.com/jmysliv/rn-playground/tree/%40jmysliv/simpler-flash-list.

Note: I've noticed that it doesn't happen every time. Sometimes it works correctly, and sometimes it scrolls to the top and the position is not maintained.

[jmysliv]

@naqvitalha Is there any progress on this one? Can I help fix it somehow? It's probably the biggest blocker for us currently.

[naqvitalha]

We're occupied with other new arch optimization. It might be a while before we get to this. I think you should be able to workaround this in your app for now. You can just scroll down on data change.

[daehyeonmun2021]

My solution here is that i called scrollToIndex without animation right after new data is loaded. We fetch fixed amount of messages with onStartReached callback.

[naqvitalha]

Hi! This issue may have been addressed by #2138. Since this issue is quite old, we're going to close it. If you're still experiencing this on the latest version, please open a new issue and we'll look into it. Thanks!