CheckBox in RecyclerView keeps on checking different items

That's an expected behavior. You are not setting your checkbox selected or not. You are selecting one and View holder keeps it selected. You can add a boolean variable into your ObjectIncome object and keep your item's selection status.

You may look at my example. You can do something like that:

public class AdapterTrashIncome extends RecyclerView.Adapter<AdapterTrashIncome.ViewHolder> {

    private ArrayList<ObjectIncome> myItems = new ArrayList<>();

    public AdapterTrashIncome(ArrayList<ObjectIncome> getItems, Context context){
        try {
            mContext = context;
            myItems = getItems;
            }catch (Exception e){
            Log.e(FILE_NAME, "51: " + e.toString());
            e.printStackTrace();
        }
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        public TextView tvContent;
        public CheckBox cbSelect;

        public ViewHolder(View v) {
            super(v);
            tvContent = (TextView) v.findViewById(R.id.tvContent);
            cbSelect = (CheckBox) v.findViewById(R.id.cbSelect);
        }
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, final int position) {
        final ObjectIncome objIncome = myItems.get(position);
        String content = "<b>lalalla</b>";
        holder.tvContent.setText(Html.fromHtml(content));

        //in some cases, it will prevent unwanted situations
        holder.cbSelect.setOnCheckedChangeListener(null);

        //if true, your checkbox will be selected, else unselected
        holder.cbSelect.setChecked(objIncome.isSelected());

        holder.cbSelect.setOnCheckedChangeListener(new OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    //set your object's last status
                    objIncome.setSelected(isChecked);
            }
        });

    }
}

In short, its because of recycling the views and using them again!

how can you avoid that :

1.In onBindViewHolder check whether you should check or uncheck boxes. don't forget to put both if and else

if (...)
    holder.cbSelect.setChecked(true);
else
    holder.cbSelect.setChecked(false);

2. Put a listener for check box! whenever its checked statues changed, update the corresponding object too in your myItems array ! so whenever a new view is shown, it read the newest statue of the object.