NestedScrollView transparent inside CoordinatorLayout but: i do not want it to be transparent

Question

here i am asking for your help.

I'm trying to implement a nestedscrollview inside a coordinatorlayout with some other stuff but the nestedscroll view keeps transparent no matter what i do.

I have already thought a lot but couldn't find any solution.

I want it to have a "solid" white background not this (+/- 30% white) background, here as some printscreens:

Before

Then when i start it sliding:

After

As we can see it the background text (that is inside the coordinator but out the nested) still readable and i can even start actions like press the drawer button that should be hidden.

Here is my main layout code which hold the NestedScrollView:

<androidx.coordinatorlayout.widget.CoordinatorLayout 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=".MainActivity">

    <androidx.core.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/white"
        android:scrollbars="none"
        app:behavior_hideable="true"
        app:behavior_peekHeight="64dp"
        app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior">

        <include layout="@layout/fragment_fast_access" />

    </androidx.core.widget.NestedScrollView>

    <com.google.android.material.appbar.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/transparent"
        android:theme="@style/AppTheme.AppBarOverlay">

        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="@android:color/transparent"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </com.google.android.material.appbar.AppBarLayout>

    <include layout="@layout/content_main" />

</androidx.coordinatorlayout.widget.CoordinatorLayout>

And this is the Fragment i want to show inside it:

<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=".FastAccessFragment">

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/guideline2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_begin="288dp" />

    <androidx.cardview.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="64dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="match_parent"
            android:layout_height="64dp">

            <ImageView
                android:id="@+id/fastAccess_inCard_coverAlbum"
                android:layout_width="48dp"
                android:layout_height="48dp"
                android:layout_gravity="center"
                android:layout_marginStart="16dp"
                android:contentDescription="@string/album_cover"
                android:scaleType="centerCrop"
                android:src="@drawable/gradient_bg_main"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <TextView
                android:id="@+id/fastAccess_inCard_songName"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_marginHorizontal="16dp"
                android:layout_marginBottom="2dp"
                android:ellipsize="end"
                android:gravity="bottom"
                android:maxLines="1"
                android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                android:textColor="@android:color/black"
                app:layout_constraintBottom_toTopOf="@id/fastAccess_inCard_artistName"
                app:layout_constraintEnd_toStartOf="@id/fastAccess_inCard_buttonPlay"
                app:layout_constraintStart_toEndOf="@id/fastAccess_inCard_coverAlbum"
                app:layout_constraintTop_toTopOf="parent"
                tools:text="Song name" />

            <TextView
                android:id="@+id/fastAccess_inCard_artistName"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:layout_marginHorizontal="16dp"
                android:ellipsize="end"
                android:maxLines="1"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@id/fastAccess_inCard_buttonPlay"
                app:layout_constraintStart_toEndOf="@id/fastAccess_inCard_coverAlbum"
                app:layout_constraintTop_toBottomOf="@id/fastAccess_inCard_songName"
                tools:text="Artist" />

            <ImageButton
                android:id="@+id/fastAccess_inCard_buttonPlay"
                android:layout_width="32dp"
                android:layout_height="32dp"
                android:layout_marginEnd="16dp"
                android:background="?attr/selectableItemBackgroundBorderless"
                android:clickable="true"
                android:contentDescription="@string/button_play"
                android:focusable="true"
                android:src="@drawable/ic_play"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@id/fastAccess_inCard_buttonPlaylist"
                app:layout_constraintTop_toTopOf="parent" />

            <ImageButton
                android:id="@+id/fastAccess_inCard_buttonPlaylist"
                android:layout_width="32dp"
                android:layout_height="32dp"
                android:layout_marginStart="8dp"
                android:layout_marginEnd="16dp"
                android:background="?attr/selectableItemBackgroundBorderless"
                android:clickable="true"
                android:contentDescription="@string/show_playlist"
                android:focusable="true"
                android:scaleType="centerCrop"
                android:src="@drawable/ic_playlist"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent" />
        </androidx.constraintlayout.widget.ConstraintLayout>
    </androidx.cardview.widget.CardView>

</androidx.constraintlayout.widget.ConstraintLayout>

Thanks in advance ;)