I am facing problem in preview pdf file in mini app sandbox app. On simulator, when i try to preview pdf, A pop appears saying PDF simulation preview successful. To preview, please go to real machine debugging. From download button, I am able to download the pdf in my machine.
But on sandbox device, It does not work. I got error saying "The file type is not PDF". Here is the code.

my.downloadFile({
    url: fileUrl,
    success: (res) => { 
      my.hideLoading();
      console.log(res);
      if(!res.apFilePath){
        my.alert({ title: 'Download Failed', content: "File not found" });
      }
      const filePath  = res.apFilePath;
    
     
      my.openDocument({
        filePath: filePath, 
        success: () => {
          console.log('PDF Opened successfully');
        },
        fail: (res) => {
          my.alert({ title: 'Error opening file', content: JSON.stringify(res) });
        }
      });
    },
    fail: (res) => {
      my.hideLoading();
      my.alert({ title: 'Download Failed', content: JSON.stringify(res) });
    }
  });

on sandbox app, when i try to open preview PDF, it fails and gave error in alert

Download Failed.       
ariver_ext: "za.co.vodacom.vodapay.appcontainer.plugin.mva.NewDownloadFileExtension"
error: -1
errorMessage: "The file is not of PDF type"
message: "The file is not of PDF type"