When I see a folder with zero (0) bytes, I have a tendency to hit cmd-delete to put it into the trash, and then cmd-shift-delete to empty the trash. A habit I must now unlearn, or possibly suffer data loss.
After 5 minutes or so, the Finder finally updated the folder size. If I am to guess, I’d say the same ge turning everything into a Spotlight search (as in Apple Mail and the File Open/Save dialogs) are responsible for this dangerous new behavior.
When will this rampant Apple incompetence, Apple Core Rot, end? The trend is only worse, never better. I have yet to see bugs introduced up to two years ago addressed. New bugs just keep piling onto the manure pile.