Why I can’t open your archieve files with WinZip?
The problem is not related with script. Script has no bugs. The problem occurs because of the Linux Server installed on your host.
So that ZipArchive plugin installed on your Linux server Archives files in SFX-ZIP format. And Winzip (somehow) can not open SFX-ZIP files. It can only unzip ZIP formatted files.
But WinRar is capable to open ZIP and SFX-ZIP formatted files.