You might be missing a LayoutManager on the RecyclerView. Without this, the RecyclerView won't know how to arrange its child views, leading to no data being displayed.

dummyRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));

Here’s a full guide from @Alex Mamo post on how to display data from Firestore into a RecyclerView using Android.

I hope this information helps to resolve your issue.