Ruby on Rails and rubyzip: powerpoint modification corrupted on windows

Question

I'm using ruby on rails to modify a powerpoint presentations existing template's xml files (open xml) based on data from my postgres database.

The issue I am facing is that after the file is generated and downloaded from heroku using a windows machine, microsoft powerpoint detects the file as corrupted and attempts to repair. After repairing the file generated in powerpoint, the file opens correctly.

If i download the file from a Linux machine and send the file to a windows machine, the file opens correctly without warning or attempt to repair. The powerpoint generated also opens correctly on Open office.

Technically, these are the steps that I am using to generate the file.

1. Open the template from the assets folder of my application
2. Extract the files in a tmp folder using Rubyzip gem
3. Open and modify the individual files using Nokogiri
4. Compress the file to a .pptx file
5. Upload/Save file using active storage

6. Redirect user to the file for download

7. Extract files method

   def self.extract_files(dir_prefix)

   Zip::File.open(Rails.root.join('app', "assets", "ppt", 'test_8.pptx')) do |z|
       z.each do |f|
   
           ##Extract files in a directory 
           f_path=File.join("tmp/#{dir_prefix}_destination", f.name)
           FileUtils.mkdir_p(File.dirname(f_path))
           z.extract(f, f_path) unless File.exist?(f_path)
   
       end              
   end
   

   end

Opening files for manipulations using:

chartxml = File.open(Rails.root.join('tmp', tmp_extract_folder, 'ppt', 'charts', 'chart5.xml'))
##Manipulation logic here
File.write(Rails.root.join('tmp', tmp_extract_folder, 'ppt', 'charts', 'chart5.xml'), doc.to_xml)

Re-zipping files using:

zf =ZipFileGenerator.new("tmp/#{dir_prefix}_destination", "tmp/#{dir_prefix}_zipped.pptx")

The implementation of the zip file generator is the same as the one provided on Rubyzip's github repo

I'm then storing using active storage using:

    ppt = Powerpoint.new(name: "#{dir_prefix}") 

    ppt.file.attach(
        io: File.open("tmp/#{dir_prefix}_zipped.pptx"), filename: 'Synthese.pptx', content_type: 'application/vnd.openxmlformats-officedocument.presentationml.presentation'
    )
    ppt.save

    render :js => "window.location = '#{download_ppt_path(dir_prefix: dir_prefix)}'" 

The user then downloads the file:

ppt = Powerpoint.where(name: dir_prefix)
redirect_to rails_blob_path(ppt.first.file, disposition: "attachment")

I tried uncommenting the code which does the manipulation of the xml files, and just unzipping and rezipping; I still face the same issue.