Last item of any section is behind of section header

[HamedMohtadi]

@sangcomz Hi.
this is my item.xml code:

<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">


    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/mainlayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        >

        <...

    </androidx.constraintlayout.widget.ConstraintLayout>

</androidx.cardview.widget.CardView>

and other part of code is exactly your example code.
but here is the result:

EDIT:
The result has captured from android emulator with API 29.
on the real devices and other emulators like NOX player and etc. it's OK!