Either you have something off screen or the game is simply wrong. It wouldn't be the first time block count has been off in this game.
The center layer is the only one that is not duplicated
Volume:
1*2+
2*2*2+
3*3*2+
4*4*2+
5*5*2+
6*6*2+
7*7=231
lel
Don't believe me do it manually yourself.
Seems fine to me.
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