iCloud Drive storage online not matching iCloud storage in MacBook settings

I noticed that my iCloud was pretty full so I checked the iCloud storage in Settings -> iCloud -> Manage and I saw that my Drive was tasking up 18GB, however when adding up the different element in iCloud I noticed there was a mismatch between the total I could compute and what was displayed so I tried to investigate further. I checked the size of my local iCloud folder which is 58GB (including my biggest files having the .nosync extension, which in total adds to 20 to 30GB that are not supposed to be synced with iCloud). Since I still couldn't explain why my iCloud was so full, I went online and that's were I discovered that there, my Drive was taking up 116GB of storage! The problem is that online I can't easily see which files and folders are taking up the most space. I just verified some of my .nosync files that are indeed not present so that's ok but for the rest I have no idea why there is a discrepancy between my iCloud Drive size locally (both in the Finder and in the Settings) and online. Is it a problem with iCloud syncing directly ?