I just purchased and installed Object Desktop and fired up SpaceMonger to help me manage the space on my laptop.
The first large files I have investigated have both turned out to be un-synced Once Drive for Business files.
Used space on my HDD is reported as 100% by SpaceMonger (Actual usage is closer to 60%)
Free space appears to be reported about right.
There's something not right here. I have a hunch this is something to do with the difference between OneDrive for Business (AKA Sharepoint) vs One Drive Personal, but this renders the application largely useless for me.
I can see other posts about similar issues. Is this a known bug that is being resolved?
Running Window 10 Pro 21H1 (19043.1826)