VirtualizingStackPanel scrolls more than expected when receiving a Reset event.

[mpylon]

Describe the bug

When clicking the "Page Down" portion of a ScrollBar, I have seen the ScrollViewer scroll multiple pages at a time. This only seems to occur when using the VirtualizingStackPanel. You can see this in the following image.

Expected: 83rd element is the topmost element.
Actual: 118th element is the topmost element.

To Reproduce

This can be reproduced by using the following sample code.

https://github.com/mpylon/ava-virtualization/tree/master

Expected behavior

Clicking the "Page Down" portion of the ScrollBar should only scroll one page, not more than one.

Avalonia version

11.2.999-cibuild0050152-alpha

OS

Windows

Additional context

No response