Navigation bar does not hide in response to nested ScrollView scrolling events

My layout is constructed with a root CoordinatorLayout, with an embedded AHBottomNavigation view with layout_gravity set to bottom, and a ScrollView within a container FrameLayout (part of a fragment). Translation behaviour is enabled.

With a RecyclerView, the AHBottomNavigationBehavior's onNestedScroll method triggers in response to user scroll, with a ScrollView, this does not happen.

Any ideas what I'm doing wrong?

Start with AHBottomNavigationBehavior.onNestedScroll and compare how it is triggered by the mentioned RecyclerView versus the nested ScrollView inside the CoordinatorLayout and FrameLayout. Reproduce the layout with translation behavior enabled, then determine why ScrollView scrolling does not reach the behavior; done means the bottom navigation hides during ScrollView scrolling as it does with RecyclerView.

Written by the indexing model from the issue text.