I removed android:theme from AndroidManifest.xml:
<activity android:name="net.geographx.MainActivity"
android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density"
android:label="@string/app_name"
android:theme="@style/AppTheme"
android:launchMode="singleTask"
android:screenOrientation="portrait"
android:exported="true">
<!-- Splash screen -->
<meta-data android:name="android.app.splash_screen_drawable" android:resource="@drawable/splash"/>
<!-- Splash screen -->
and removed apptheme.xml from platform\android\res\values directory:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="AppTheme" parent="@android:style/Theme.DeviceDefault.NoActionBar">
<item name="android:windowBackground">@drawable/splash</item>
</style>
</resources>
https://forum.qt.io/topic/99541/how-to-have-a-splash-screen-in-android-application-built-with-qml/3
<meta-data android:name="android.app.splash_screen_drawable" android:resource="@drawable/launch_logo"/>How to display the splash screen immediately when Qt/QML android app is launched?
https://stackoverflow.com/questions/64108523/how-to-display-the-splash-screen-immediately-when-qt-qml-android-app-is-launched