Android UI, Floating Action Button gets covered up by softkeyboard after EditText focus followed by screen rotation

Question

Problem is as per the title. I have a floating action button at the right-bottom screen corner. When clicking on some editText field, then this button floats nicely to the top of the onscreen keyboard as per screenshot:

Problems start if I have focus set on editText view and then rotate the screen. After that point onwards whenever I click on editText field then the keyboard comes up but the floating button does not, so it gets covered up by the keyboard.

Like this:

After this happens, it does not matter if I move between frames or do some activities. The problem stays and this behaviour appears throughout the app wherever I have some editText fields and a floating button, it won't float with the keyboard. It just gets covered up by the keyboard. Things return to normal only after I have completely closed the app and restarted.

Now I'm still newbie when it comes to Android development, so I'm not sure what more info I could/should provide. I'm using Android Xiaomi P30 pro for testing (if it makes any difference).

android settings

compileSdkVersion 29
buildToolsVersion "30.0.0"

defaultConfig {
    applicationId "ee.taltech.mobile.contacts"
    minSdkVersion 26
    targetSdkVersion 29
    versionCode 1
    versionName "1.0"

Resource for button and editTxt fields

<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"
    android:padding="16dp"
    tools:context=".fragments.AddPersonFragment">

    <EditText
        android:id="@+id/addContactValue_edit"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="16dp"
        android:ems="10"
        android:hint="First Name"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/addLastName_edit"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_marginTop="16dp"

        android:ems="10"
        android:hint="Last Name"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/addContactValue_edit" />


    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/add_person_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="24dp"
        android:layout_marginBottom="24dp"
        android:clickable="true"
        android:focusable="true"
        android:src="@drawable/ic_check"
        android:tint="@android:color/white"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>