"/data get" returns slot number when getting item NBT

To reproduce:

1. Have stones in your e.g. fourth hotbar slot, but nowhere else.
2.

/execute store result score @s scoreName run data get entity @s Inventory[{id:"minecraft:stone"}]

Result: Your score in the scoreboard "scoreName" becomes 3, like the slot number.

Expected: Either 1 for success or, better: The number of matching slots. Currently this command fails and stores the number 0 if there are multiple stacks of stone.