Troubleshooting & messages · Free space and clean-up messages
Why can't a short period be broken down folder by folder?
Short answer: Folder sizes are measured once a day to keep the app light, so shorter periods can't be split by folder. Choose a longer period or wait for the next daily reading.
Storage Studio measures folder sizes once a day to stay light on your Mac. A period shorter than that falls between two readings, so it can't say which folder changed — everything else on the screen is still measured.
Pick a longer period, or wait for the next daily reading. Readings that were never taken can't be recreated later.