Without seeing all fields, it’s hard to see what you describe.
It looks correct to me except a blank entry (I achieved that with play on my system when the folders weren’t grouped together (top or bottom), and the blank space represents a folder which makes sense to me) and the final 2.8GB. Is it the 2.8 GB that you’re asking about?
We have no idea what that line represents, which limits our capacity to understand what is happening and why it happens. What type of file is it?, what do you get when you ask the system (ie. using
Note: My exploration wasn’t on focal but impish; where I was unable to re-create what you describe except for the space in the listing. If I had details of what type(s) of files you were displaying & couldn’t re-create it on my impish system, I’d have tried a focal one, but I have no idea what types of files you’re using as you only show the size column