Temporary 'Cloud transfer' download clogs up my internal SSD

I have 900 pictures in a Cloud album. I use Capture One with an external SSD with a lot of free space. My internal SSD is almost full. 

When attempting to download the 900 images from the cloud to my Capture One Catalog they FIRST get downloaded to the internal SSD before Capture One moves them to the external drive. However, the internal SSD doesn't have enough space so hold all those images. So I get an error message and the process stops. The images don't get imported. BUT the temporarily downloaded images ALSO do not get deleted.

I have been searching and searching but  I cannot find the folder where this temporary download goes. 

Anyone?