Zipped File is Deleting Random PDF Files
I created a larger file at 328 mb to post online for products I sell to teachers compiled of about 25 individual files. Most of the files were saved as a pdf, but there is one video and a few PowerPoints also. I placed individual files in folders and then zipped the whole thing before I uploaded it. I have double checked on my Mac computer a handful of times if everything is there. I downloaded the product on another computer and about 4 files aren't there...yet they WERE there when I uploaded it. What is going on? I also tried to compress files but they didn't compress much. I have buyers that need the products. It is also taking maybe 50 minutes to upload it. What is happening?
MacBook Pro