Downloading multiple files from iCloud Drive to PC doesn't work completely...

I'm trying to download files from my iCloud Drive to a local drive on my PC and am able to select the files to download, but when I click the Download icon:only a portion of the files selected download correctly. The number of files that actually download is not even consistent: If I select 780 files approximately 370 download; If I select 100 about 54 download, and if I select 50 files, only 36 download...

What gives?

Thanks for your help,

Steve