List View Constrain jump to top

Question

I am trying to learn SQL database with a tutorial. I add user and age to database and get them back and displayed using listView using ViewAll button then if i trying to add another user the list view jump to top how can i fix this i am a noob need help

XML

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/lv_customerList"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<EditText
    android:id="@+id/et_namex"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="@string/CustomerName"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<EditText
    android:id="@+id/et_agex"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:ems="10"
    android:hint="@string/Age"
    android:inputType="number"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/et_namex" />

<Switch
    android:id="@+id/Sw_activex"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/ActiveCustomer"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/et_agex" />

<Button
    android:id="@+id/btn_viewAllx"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginTop="8dp"
    android:text="ViewAll"
    app:layout_constraintEnd_toStartOf="@+id/btn_Addx"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/Sw_activex" />

<Button
    android:id="@+id/btn_Addx"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Add"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toEndOf="@+id/btn_viewAllx"
    app:layout_constraintTop_toTopOf="@+id/btn_viewAllx" />

<ListView
    android:id="@+id/lv_customerListx"
    android:layout_width="410dp"
    android:layout_height="563dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.5"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.988" />

    </androidx.constraintlayout.widget.ConstraintLayout>

this is how its look when its run

in xml design