hidden files
I have the same problem.
I have used Disksweeper, Whatsize (purchased version in Admin mode), "About Mac", Finder (showing all hidden files), and CCleaner. All are consistent - I have c. 150 GB of unidentified "other" files. I have read the Apple
https://support.apple.com/en-us/HT202867 which is mostly irrelevant.
I have found the caches (deleted them), swap files, hidden files,Trash, files from other users, V100 backups, etc., and STILL have a 150 GB discrepancy. Run Disk Permission, Disk Verify, rebooted in Safe Mode, cleaned out tons of various caches, re-indexed Spotlight, nothing makes a difference in the "other" files. It reduces my actual files, of course, so I have more user space.
In Finder with all files shown (and the other programs) the sum of the files and folders does not add up to the total, by 150 GB. Total disk size is correct (500GB SSD).
Any suggestions? Driving me crazy. It seems the space is not occupied by actual files, but is allocated to something else.