If you select a folder in the 'Copy to' task, the folder will not be copied down to the system targeted.
If you look in the DStasks.log file it will show that DS is trying to map a drive to the zip file. Mapping to a file is not supported.
The 'Copy to' task is trying to map the drive to the zip file.
The issue has been resolved in 8.5 RU2 due out second quarter 2019.