I try to learn Unity and I don’t undestand its logic.
Empty scene with one light and a sky: batches = 1
Added one cube: batches = 1
Added the second cube: batches = 7. WHY??
Removed the first cube: batches = 6. WHY??
Why have I 6 batches with removed the second cube? Why the first cube better than the second cube for Unity?
The only “bug” is that the stats window doesn’t refresh unless you either click on the game window (which you’re not doing) or make some other change to refresh the editor.
So your observations are all one behind.
Try adding one cube and then clicking in the game window. I expect you’ll see 6 batches. Then add another cube and click in the game window - batches are now 7. Remove the first cube, batches are back to 6 again.