FAB button not showing drawable properly inside android studio layout editor

Question

I cannot seem to get the FAB button preview to work properly.

<com.google.android.material.floatingactionbutton.FloatingActionButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:contentDescription="@string/email_icon"
    app:srcCompat="@android:drawable/ic_dialog_email"/>

The dependency - implementation 'com.google.android.material:material:1.2.1'

Preview

I have tried to change the drawable being shown to a normal vector image and also change app:srcCompat to android:src but no luck:(

I read that it may be a bug in the android studio - I have the 4.1.1 version installed.

Style/Theme file contents

<resources xmlns:tools="http://schemas.android.com/tools">

<!-- Base application theme. -->
<style name="Theme.Kotlin" parent="Theme.MaterialComponents.DayNight.DarkActionBar">

    <!-- Primary brand color. -->
    <item name="colorPrimary">@color/cyan</item>
    <item name="colorPrimaryVariant">@color/cyan_dark</item>
    <item name="colorOnPrimary">@color/white</item>

    <!-- Secondary brand color. -->
    <item name="colorSecondary">@color/green</item>
    <item name="colorSecondaryVariant">@color/green_dark</item>
    <item name="colorOnSecondary">@color/black</item>

    <!-- Status bar color. -->
    <item name="android:statusBarColor" tools:targetApi="l">?attr/colorPrimaryVariant</item>

    <!-- Customize your theme here. -->

</style>

Color file contents

<resources>
    <color name="black">#FF000000</color>
    <color name="white">#FFFFFFFF</color>
    <color name="cyan">#006064</color>
    <color name="cyan_light">#428e92</color>
    <color name="cyan_dark">#00363a</color>
    <color name="green">#81c784</color>
    <color name="green_light">#b2fab4</color>
    <color name="green_dark">#519657</color>
</resources>

Manifest file contents

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/Theme.Kotlin">

    <meta-data
        android:name="preloaded_fonts"
        android:resource="@array/preloaded_fonts" />

    <activity
        android:name=".MainActivity"
        android:label="@string/tip_time">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

Answer 1

Change material theme implementation to 'com.google.android.material:material:1.2.0-alpha02' . Because new release of Material Theme library is buggy. Simply restart Android Studio after gradle sync if problem not fixed.