OnStartup Android app - white screen

Question

OnStartup Android app - white screen

The well-known onStartup white screen issue appears along with my application (only from yesterday), but I cannot resolve any sentence read in the following threads:

and a few more.

Not only onStartup, there is also some intermittent white screen for 5-10 seconds between them. This happens with both assembly assembly and release.

The following is the code I'm using:

styles.xml:

<style name="Theme.Transparent" parent="Theme.AppCompat.Light.NoActionBar">
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowActionBar">false</item>
    <item name="android:windowFullscreen">true</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowIsTranslucent">true</item>
</style>

Manifesto:

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:hardwareAccelerated="true"
    android:theme="@style/AppTheme">

    <activity
        android:name=".MainPlayer"
        android:configChanges="orientation|keyboardHidden|screenSize"
        android:theme="@style/Theme.Transparent"></activity>

    <activity
        android:name=".RegisterActivity"
        android:configChanges="orientation|keyboardHidden|screenSize"
        android:theme="@style/Theme.Transparent">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

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

    <receiver
        android:name="com.blynq.app.services.BootReceiver"
        android:permission="android.permission.RECEIVE_BOOT_COMPLETED"
        android:theme="@style/AppTheme">
        <intent-filter>
            <action android:name="android.intent.action.SCREEN_ON" />
            <action android:name="android.intent.action.BOOT_COMPLETED" />
            <action android:name="android.intent.action.MY_PACKAGE_REPLACED" />
        </intent-filter>
    </receiver>

</application>