Android: SoftKeyBoard cover up MultiLine edittext

Question

I have a multi-line editText inside a scrollView follow by a button.

If using adjustPan, the softkeyboard cover up the whole editText, leaving only the first line.

When using adjustResize, even the button shows up which is worst

Here is my 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toTopOf="@id/btn_save">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <TextView
                android:layout_width="match_parent"
                android:layout_height="600dp"
                android:background="@color/LightBlue"/>

            <androidx.appcompat.widget.AppCompatEditText
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Enter text"
                android:inputType="textMultiLine"
                android:singleLine="false"
                android:gravity="top"
                android:minLines="8" />

        </LinearLayout>

    </ScrollView>

    <com.google.android.material.button.MaterialButton
        android:id="@+id/btn_save"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Save"
        android:clickable="false"
        app:backgroundTint="@color/gray_jll"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

What I want (temporarily achived using gravity bottom, but of course we want the text to display on the top using gravity top)

I looked at Android soft keyboard covers EditText field. But I am not using full screen mode. android:isScrollContainer="true" does nothing.

Please tell me what is causing this. Thanks in advance.