All things related to the balance of the game can be changed when deemed necessary by the game designers. This issue is no exception. At some point in the game, the game designers changed the limit per level with counters and stoves and right now, you may be able to put less counters/stoves in your cafe than before. Fear not! Changes like these are made to ensure a better gameplay for everyone who plays the game.

If you were able to put - let's say - 10 counters in your cafe and now the game lets you put 9, this is due to the balance changes. The same goes for when you already have 10 counters in your cafe and you put 1 of them in your inventory and now the game does not let you put it back. Please do not worry as this is not a bug and due to balance changes.

Hope this helps!