Finder's free space not accurate
My 1TB MacBook Pro now has around 180 GB free after I backed up two iOS devices via iTunes (for a total of 75 GB). I deleted those backups and restarted, and no change in the Finder-reported free space. Even worse, I use Dropbox's new online-only file sync, so that files are reported by the Finder as 0 kb unless I actually download them. But according to Grand Perspective, while I have around 500 GB freed up this way, it still only looks as if I have around 180 GB free no matter what I do. Thoughts?
MacBook Pro 15”, macOS 10.14