after "extendBodyBehindAppBar: true in Scaffold" The view show under appbar

[SalarPro]

I have a list view but when I use the "extendBodyBehindAppBar: true ", the view have margin from the appbar,
how ever when i use
Scrollbar(
child: PaginateFirestore(...),
)

it over flow the window.

Scaffold( extendBodyBehindAppBar: true, extendBody: true, ...)

here is a video about :
1-In the Search Tab i used the Scrollbar(child: PaginateFirestore(...))
2-in the Home Tab I used the ListView(children: [...])

screen-recording-2022-04-15-at-44701-am_Wi6yczND.mp4