How to disable CollapsingToolbar's collapse when scroll has not content?

get your appbarlayout reference and set the setScrollFlags.

AppBarLayout.LayoutParams p = (AppBarLayout.LayoutParams) toolbar.getLayoutParams();
p.setScrollFlags(0);
toolbar.setLayoutParams(p);

Try appbarParams.setScrollFlags(-1); and appBarLayout.setExpanded(true, true) to remove the elevation.

And if you have recyclerView in the fragment, try recyclerView.setNestedScrollingEnabled(false);

Need to disable expand on CollapsingToolbarLayout for certain fragments