Items when grouped act as 1 entity, cannot perform @e[limit=1] commands on them

So I've been trying to make a datapack which kills a single item entity from a stack of item entities on the floor. However when the items group for some reason they count as one single entity even when doing /kill @e[type=minecraft:item,limit=1] (notice how it says killed raw salmon not 64 entities)... I'm not too sure if this is a bug or not but It's been annoying me forever and I couldn't think of any way to get around it.