What FTP client software is being used?
I recommend trying different FTP client applications to rule-out possible issues in the FTP client.
I would also double check to ensure the source files are not already corrupted. Alternatives to FTP may include SFTP (using the SSH protocol),
cPanel Web Disk (using WebDAV over HTTP or HTTPS),
cPanel File Manager, or
cPanel Legacy File Manager; once the upload is completed I recommend attempting to extract the archive via cPanel File Manager. Please note that SFTP does not require full SSH access.
Here are a few SFTP clients that I may consider:
FileZilla, for Linux, Mac, and Windows
Cyberduck, for Mac
WinSCP, for Windows