Hi waylana,
Are you using Apple's provided iCloud > iCloud Drive > Desktop & Documents Folder, wherein it is copied to your iCloud Drive from your Mac? If so, that is the likely cause. The reason is the entire contents of the Desktop and Documents Folder must be synched up and then down to your Mac, when also attempting to do the action you want.
What I would suggest is unless you really need this function enabled, be more selective about what content you sync between your devices via iCloud.
If it might, don't sync the entirety of either; but setup new folders in iCloud that you then create content in that you want dedicated synching for via iCloud and disable the Desktop & Documents Folder sync via iCloud.
What I mean is something like this:
- Disable the Desktop & Documents Folder sync is iCloud Drive
- Create a new folder in iCloud, name it as you want to
- If you know how, create an Alias for that folder in iCloud, and then move it into your Documents Folder
I hope this helps.
Cheers,
Anthony