Hello,

I have an ItemsControl where the ItemsPanelTemplate is a VirtualizingStackPanel with IsVirtualizing="True", VirtualizationMode="Recycling" and ScrollUnit="Pixel".
The Template is a controltemplate with a the following hierarchy: Border -> ScrollViewer -> ItemsPresenter.

In the bound items (an observable collection) I have several items that could be of different types (all inheriting from the same VM ancestor). Those items of different types exposes different properties.
I then have different datatemplate for those items depending on the type. When there is a textbox, a combobox or a checkbox,

When the view is rendered, if I just scroll, everything works fine.
As soon as I click on one of those controls, the next time I'm scrolling, it will go directly to the bottom of the items control.

By searching into the forum, I saw issue I was able to "fix" the issue by simply adding a behavior that, when attached to the VirtualizingStackPanel, will simply subscribing to the RequestBringIntoView event.
In the handler, just marking the event as being Handled is enough: e.Handled = true;
This is not enough as this is not allowing key navigation. However it fixed it, and, hopefully, should help you better understanding what's happening!