This is why you should…
…with that FTP client, and not rely on the File Manager, because if the zip file is bigger than 10 MBs it will be deleted from the system because of a file size limit explained in this article:
And even if you manage to upload it successfully, extracting it through the File Manager is not a native process in FTP, so the server has to download the zip file, extract it on its side and then upload the extracted folder, and since the File Manager is also shared, the server doesn’t have enough power to do that and that function will eventually fail.