Unable open file using file_picker & open_file.dart

iam trying to open a file by using file_icker.dart & open_file.dart. iam using AS articfox, flutter 2.5 and android 11 (did tried on emulator and androdi device (Remi note)).

this is my openFile code:

void _openFileExplorer() async {
    setState(() => _loadingPath = true);

    try {
      _directoryPath = null;
      _paths = (
          await FilePicker.platform.pickFiles(
            type: _pickingType,
            allowMultiple: _multiPick,
            onFileLoading: (FilePickerStatus status) => print(status),
            allowedExtensions: (_extension?.isNotEmpty ?? false)
            ? _extension?.replaceAll(' ', '').split(',')
            : null,
          )
      )?.files;
    } on PlatformException catch (e) {
      print("Unsupported operation" + e.toString());
    } catch (ex) {
      print(ex);
    }

    if (!mounted) return;

    _loadingPath = false;
    _fileName =
      _paths != null
          ? _paths!.map((e) => e.name).toString()
          : '...';
    if (_paths != null) {
      print("FILEPATH FOUND==> $_paths");
      //try crating File using path
      File file = File(_paths.toString());
      //checking file exist
      (await file.exists()) ? print("file exist") : print("file !exist");
      //what the hell...try open it !!
      final _result = await OpenFile.open(_paths.toString());
      print("result: "+ _result.message);
    }
    else {
      print("nope");
    }
  }

and This is the output:

D/FilePickerUtils( 9666): File loaded and cached at:/data/user/0/com.example.bismillah/cache/file_picker/pdf_tmp_fie.pdf
D/FilePickerDelegate( 9666): File path:[com.mr.flutter.plugin.filepicker.FileInfo@98399df]
I/flutter ( 9666): FilePickerStatus.done
I/flutter ( 9666): FILEPATH FOUND==> [PlatformFile(path: /data/user/0/com.example.bismillah/cache/file_picker/pdf_tmp_fie.pdf, name: pdf_tmp_fie.pdf, bytes: null, readStream: null, size: 5948832)]
I/flutter ( 9666): file !exist
I/flutter ( 9666): result: the [PlatformFile(path: /data/user/0/com.example.bismillah/cache/file_picker/pdf_tmp_fie.pdf, name: pdf_tmp_fie.pdf, bytes: null, readStream: null, size: 5948832)] file does not exists

What confused me is that file_picker clearly confirmed the selected file :

File loaded and cached at:/data/user/0/com.example.bismillah/cache/file_picker/pdf_tmp_fie.pdf

But when i tried to assign that path to a file which i planned to open with open_file.dart it said file not exist. can someone please help me understand whats goin on. Thanks