Hi All,
I know this probably isn't the solution you want to hear, but I have found a fix for now until apple releases an update to officially fix it...
Boot your Mac into safe mode > create a new folder with the .nosync on (Do not rename the folder to add .nosync) > then copy over the files/folders from the old folder to the new folder you just created with the .nosync on.
This should then not sync the folder.
You might see the iCloud icon saying awaiting upload, close the finder window and go back to the folder and the iCloud icon will be gone.
Honestly this isn't ideal at all but is a fix for now until Apple hopefully fix it in coming updates.
Instructions on how to boot into safe mode
Start up your Mac in safe mode – Apple Support (UK)
Really hope this helps!!
Thanks
Alex