Android: NotifyDataSetChanged does not work in RecyclerView.Adapter

There is a list of user chats, and the chat data is periodically updated. In service, data is received, and sent to the fragment. When data is received by a fragment, it is sent to the adapter, and the most interesting begins here. Data in the adapter is not updated.

That is, they are updated in ArrayList, but when I call notifyItemChanged (0) ;, the first item does not want to be updated. You must first scroll down and then up, and even then new data will be visible.

Adapter code (not all):

public class DialogAdapter extends RecyclerView.Adapter<DialogAdapter.ViewHolder> { private ArrayList items; private ArrayList<String> dialogPosition; public DialogAdapter(ArrayList items) { this.items = items; dialogPosition = new ArrayList(); Dialog dialog; for (int i = 0; i < items.size(); i++) { dialog = (Dialog) items.get(i); dialogPosition.add(String.valueOf(dialog.ownerId)); } } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { return new ViewHolder( LayoutInflater.from(App.context).inflate(R.layout.dialog_item, parent, false) ); } @Override public void onBindViewHolder(ViewHolder holder, int position) { /* Code */ } @Override public int getItemCount() { return items.size(); } class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { View itemView; public ViewHolder(View itemView) { super(itemView); this.itemView = itemView; } @Override public void onClick(View v) { App.openChat((Dialog) items.get(getPosition()); } } public void setMsg(String body, int chat) { int position = dialogPosition.indexOf(String.valueOf(chat)); if (position != -1) { notifyItemMoved(position, 0); Dialog dialog = (Dialog) items.get(position); dialog.body = body; items.remove(dialog); dialogPosition.remove(String.valueOf(chat)); items.add(0, dialog); dialogPosition.add(0, String.valueOf(chat)); notifyItemChanged(0); } } 

}