Recyclerview animation not working

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Android

animation

i have an activity that contains 2 fragments

StepsFragment contains a Recyclerview but the Recyclerview's animation is not working

<pre><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="400dp"
android:background="#B3D1DB"
tools:context=".StepsFragment">

<TextView
    android:id="@+id/inputEntred"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="TextView"
    android:visibility="invisible" />

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/RV"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:clipToPadding="false"
    android:layoutAnimation="@anim/layou_animation_fall_down"
    android:paddingTop="10dp"
    android:paddingBottom="30dp" />

layou-animation-fall-down

<layoutAnimation xmlns:android="http://schemas.android.com/apk/res/android"
    android:animation="@anim/fall_down"
     android:animationOrder="normal"
       android:delay="15%">

fall-down

<set xmlns:android="http://schemas.android.com/apk/res/android" android:duration="6000">
        <translate
            android:fromYDelta="-20%"
            android:interpolator="@android:anim/accelerate_decelerate_interpolator"
            android:toYDelta="0"
            android:duration="1000" />
     <alpha
     android:fromAlpha="0"
     android:interpolator="@android:anim/accelerate_decelerate_interpolator"
     android:toAlpha="3"
         android:duration="1000"
     />
  <scale
      android:fromXScale="105%"
      android:fromYScale="105%"
      android:interpolator="@android:anim/accelerate_decelerate_interpolator"
      android:pivotX="50%"
      android:pivotY="50%"
      android:toXScale="100%"
      android:toYScale="100%" android:duration="1000"
      />
</set>

activity layout

<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:layout_width="match_parent"

android:layout_height="match_parent"
tools:context=".Sorting_activity">


<RelativeLayout
    android:id="@+id/triLayout"
    android:layout_width="0dp"
    android:layout_height="300dp"
    app:layout_constraintBottom_toTopOf="@+id/stepsLayout"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.0"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.0">

</RelativeLayout>

<androidx.coordinatorlayout.widget.CoordinatorLayout
    android:id="@+id/stepsLayout"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@+id/triLayout"></androidx.coordinatorlayout.widget

What I have tried:

the animation works when the activity opens the fragment in a new page , but not when the fragment is inside the activity