please run flutter_gallery sample and open sample in Material - Tabs.
issue can be reproduced in dev/master branch, beta branch has no this issue but has crash issue.

Steps to Reproduce

1. tap APPAREL and scroll to bottom(Blush Sweats)
2. tap HOME and scroll the list up or down
3. tap APPAREL the Ginger Scarf will disapper in Screen bottom

and i made a demo based on NestedScrollView. it also has this issue.
i notice that SliverOverlapAbsorber can only used for SliverAppBar, no such thing for SliverPersistentHeader. i think it also effect the scroll behaviour.
more detail please see the gif and my demo code. it's kind of you can have a look for this issue.
thanks.
demo_code.txt