pdf opened in an external app cannot save changes

Expected Behaviour

I open a pdf with the file-opener2 plugin and the acrobat reader can save its changes.

Actual Behaviour

The pdf opens correctly but the changes (for example, the signature) are not saved. I used Adobe Acrobat v21.6.0.18197

The file exists in the directory.

Platform and Version (eg. Android 5.0 or iOS 9.2.1)

Android 11 Cordova 9.0.0 Android Platform 8.0.0

(Android) What device vendor (e.g. Samsung, HTC, Sony...)

via AVD

Plugin version

3.0.5

Sample Code that illustrates the problem

// externalDataDirectory = file:///storage/emulated/0/Android/data/[APP_ID]/files/
window.resolveLocalFileSystemURL(cordova.file.externalDataDirectory, function (dir) {
    dir.getFile("15-07-21-174005_000010009647_SR.pdf", {}, function (file) {
        // nativeURL = file:///storage/emulated/0/Android/data/[APP_ID]/files/15-07-21-174005_000010009647_SR.pdf
        // also tried file.toInternalURL() = "cdvfile://localhost/files-external/15-07-21-174005_000010009647_SR.pdf"
        cordova.plugins.fileOpener2.open(file.nativeURL, "application/pdf", {
            success: function () {
                ...
            },
            error: function (oError) {
                ...
            },
        });
    }, function (oError) {
        ...
    });
});

config.xml from the app:

<access origin="*"/>
<allow-intent href="*" />
<allow-navigation href="*" />

<platform name="android">
    <icon src="www/offlineRes/img/mobile-icons/logo-header.png" density="xhdpi"/>
    <preference name="android-minSdkVersion" value="21"/> <!--Android 4.1-->
    <preference name="android-targetSdkVersion" value="29"/>
    <preference name="AndroidExtraFilesystems" value="files,files-external,documents,sdcard,cache,cache-external,root"/>
    <preference name="AndroidPersistentFileLocation" value="Internal" />
    <preference name="AndroidPersistentFileLocation" value="Compatibility" />
    <preference name="loadUrlTimeoutValue" value="700000"/>

    <custom-config-file parent="/*" target="AndroidManifest.xml">
        <uses-permission android:name="android.permission.CAMERA"/>
        <uses-feature android:name="android.hardware.camera"/>
        <uses-feature android:name="android.hardware.camera.autofocus"/>
    </custom-config-file>
    <edit-config file="app/src/main/AndroidManifest.xml" mode="merge" target="/manifest/application">
        <application android:usesCleartextTraffic="true" />
        <application android:networkSecurityConfig="@xml/network_security_config" />
    </edit-config>
    <resource-file src="merges/android/xml/network_security_config.xml" target="app/src/main/res/xml/network_security_config.xml" />
</platform>

<allow-navigation href="http://*/*"/>

pwlin / cordova-plugin-file-opener2

pdf opened in an external app cannot save changes #323