Duplicati keeps downloading from OneDrive

I set up Duplicati to backup to mu Onedrive (as part of Office365), but now all files are downloaded to my local Onedrive folder and eating up space on my hard drive. How can I prevent this?

Welcome to the forum @JanP

Using what Storage Type on your Destination screen? Microsoft OneDrive v2 would be good.

You may also have to set Duplicati destination folder to Online-only, per OneDrive directions at:

Save disk space with OneDrive Files On-Demand for Windows 10

If you now have it set to Always keep on this device, OneDrive does it (but you don’t want it).