Android 8+ (API >26) REQUEST_INSTALL_PACKAGES permission not being detected

I am implementing an APK installer for my Android app. The workflow on Android 7 executes flawlessly. However, Android 8+ is running into permission issues. Expecting this, the app is set up to detect this and asks the user for permission (REQUEST_INSTALL_PACKAGES).

Here's where I ran into my issue; even though I am granting the permission, my app does not seem to think so. This is how I handle when the user comes back from the permission settings:

ActivityResultLauncher<Intent> activityResultLauncher = registerForActivityResult( new ActivityResultContracts.StartActivityForResult(), new ActivityResultCallback<>() { @Override public void onActivityResult(ActivityResult result) { runOnUiThread(() -> { if (appHasInstallPackagePermission()) { showInstallationStep(); } else { manuallyRecheckedInstallPermission = true; showPermissionRequiredPage(); } }); } } );

It does not matter if I turn on the permission, it is always the else branch that executes, so I am back to the permissions page of my app... More of the relevant code:

if (appHasInstallPackagePermission()) { showInstallationStep(); } else { showPermissionRequiredPage(); } private void showPermissionRequiredPage() { String appName = launcherPackageInfo.getAppName(); titleTextView.setText(getString(R.string.permission_required_title)); if (manuallyRecheckedInstallPermission) { descriptionTextView.setText("..."); } else { descriptionTextView.setText("..."); } permissionButton.setOnClickListener(new View.OnClickListener() { @Override @RequiresApi(api = Build.VERSION_CODES.O) public void onClick(View v) { requestInstallPackagesPermission(); permissionButton.setText("..."); } }); permissionButton.setText(getString(R.string.grant_permission_button_text)); permissionButton.setVisibility(View.VISIBLE); permissionButton.requestFocus(); } @RequiresApi(api = Build.VERSION_CODES.O) private void requestInstallPackagesPermission() { Intent settingsIntent = new Intent( Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES, Uri.parse("package:" + getPackageName()) ); activityResultLauncher.launch(settingsIntent); }