Flutter apps displaying grey screen on apps start launch - flutter

Question

I don't know if this is normal or a bug issue, I've noticed some apps (my own included)
after making a release version or even a debug one when launch it will display a weird bronze background color few milliseconds Screenshot below) is this normal on build or is there any resolution for this ?
Or perhaps could this be related to AndroidManifest
Edit : I'll post my build gradle and AndroidManifest in case it helps
compileOptions {
sourceCompatibility 1.8
targetCompatibility 1.8
}
buildTypes {
release {
minifyEnabled true
shrinkResources true
zipAlignEnabled true
proguardFiles getDefaultProguardFile(
'proguard-android-optimize.txt'),
'proguard-rules.pro'
signingConfig signingConfigs.release
}
AndroidManifest :
<uses-feature android:name="android.hardware.camera.autofocus"/>
<uses-permission android:name="android. permission.INTERNET" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<uses-permission android:name="android.permission.WAKE_LOCK"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="com.android.vending.BILLING" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<uses-permission android:name="android.permission.ACCESS_BACKGROUND_LOCATION" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.FLASHLIGHT"/>
<queries>
<intent>
<action android:name="android.media.action.IMAGE_CAPTURE" />
</intent>
</queries>
<application
android:name="io.flutter.app.FlutterApplication"
android:label="myapp"
android:icon="#mipmap/ic_launcher"
android:usesCleartextTraffic="true"
android:requestLegacyExternalStorage="true"
>
<receiver android:name="com.app.myapp">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED"/>
<action android:name="android.intent.action.MY_PACKAGE_REPLACED"/>
</intent-filter>
</receiver>
<activity
android:name=".MainActivity"
android:launchMode="singleTop"
android:theme="#style/LaunchTheme"
android:configChanges="orientation|keyboardHidden|keyboard|screenSize|smallestScreenSize|locale|layoutDirection|fontScale|screenLayout|density|uiMode"
android:hardwareAccelerated="true"
android:windowSoftInputMode="adjustResize">
<meta-data
android:name="io.flutter.embedding.android.NormalTheme"
android:resource="#style/NormalTheme"
/>
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data
android:scheme="https"
android:host="YOUR_SUBDOMAIN.page.link" />
</intent-filter>
<intent-filter>
<action android:name="FLUTTER_NOTIFICATION_CLICK" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<meta-data
android:name="flutterEmbedding"
android:value="2" />
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="#xml/provider_paths"/>
</provider>
<meta-data android:name="com.google.android.geo.API_KEY"
android:value=""/>
<meta-data
android:name="com.google.android.gms.ads.APPLICATION_ID"
android:value=""/>
<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="#string/facebook_app_id"/>
<activity android:name="com.facebook.FacebookActivity"
android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation"
android:label="#string/app_name" />
<activity
android:name="com.facebook.CustomTabActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="#string/fb_login_protocol_scheme" />
</intent-filter>
</activity>
<service android:name="com.app.fayda.localnotifications.services.LocalNotificationsService"
android:exported="false" />
<meta-data android:name="com.google.firebase.messaging.default_notification_channel_id"
android:value="#string/default_notification_channel_id" />
Here is another example of Tinder app which has the same issue right before Splash screen appear

Answer 1

After few investigation I'll give some potential solution :
To check the logcat issue I had to change to release version build variant
(1). Flutter clean and flutter pub get
(2). Open Android Module of Project in another window
(3). Wait for all process and after that First Clean Project and Rebuild Project
(4). Wait for Rebuild process complete and now change your build variants first at your left bottom you can see tab "Build variant" open it and after that in the front of "app" folder you can see in column of "Active Build Variant" like such "debug" please change it to "release"
(5). after that repeat step 3
(6) and run project from Android Module If you face the grey screen issue then you can know what is the exactly error in Logcat section and also make sure that your keystore file and keystore details are proper for release
This is another potential solution apparently this file launch_background.xml causing this every time you start the app it will launch this first and there's no way to bypass this as far as I know you may able to change the color as you see fit or put image but there's no workaround around this unfortunately