[Bug]: Content jumping up and down when scrolling

[M1ck0]

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Summary

When I scroll on Opera on iPhone, there is a bug with the page

Page

https://react.dev/blog/2025/04/23/react-labs-view-transitions-activity-and-more

Details

Here is the video of the issue

https://www.veed.io/view/6dd44400-f747-4dac-aca5-f6578ea5d923?panel=share

[bhanushakya2004]

This is not a critical issue; it's a minor browser glitch that occurs occasionally. It's not a serious bug.

[gaearon]

cc @rickhanlonii might be nice to dig in unless we know what this is

[M1ck0]

@gaearon This looks like some component in the text is making this bug. It doesn't exist on other pages, even tho the layout is same

[M1ck0]

@bhanushakya2004 it occurs always on this page on every browser. To me, and probably other users, it is really annoying, since I can't read the part of the text without doing gymnastics on the page.

[rickhanlonii]

Yeah I'm seeing this on other pages too, it's super super annoying. I think the issue is that when the sandboxes are loaded in the scroll position changes, but that was working before so I'm not sure what broke.

[BartoszKlonowski]

I can repro this even in the markdown preview in VS Code, especially around the "Animating navigations" sandpack. @rickhanlonii Let me take a look please, maybe I'll be able to fix this.

[rickhanlonii]

Yeah, please take a look