Floating Action Button icon image not showing after hide and show

I know it has been a long time since you posted this but I had the same problem. I solved it by doing a hide() and then a show() to the fab after clicking. (In my particular case I change the drawable in onClick. Doing hide() and show() after changing the drawable solved the issue).

Your code shall look like:

fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (sheetBehavior.getState() != BottomSheetBehavior.STATE_EXPANDED) {
                    sheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED);
                    fab.setImageResource(R.drawable.ic_close);
                } else {
                    sheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
                    fab.setImageResource(R.drawable.ic_filter);
                }
                fab.hide();
                fab.show();
            }
        });

Did face the same issue with dependency com.google.android.material:material:1.0.0. Upgrading the version to 1.1.0-alpha3 fixed the issue.