Invisible item in inventory and can bee seen in furnace

somehow I had a stack of 64 Cobblestones that was hidden in my (inventory) but showed up in the (furnace) on the left side of the items I could use to craft.
There is a work around by placing the cobblestone in the crafting area and retrieving them from there to show up in your inventory.

note: i'm not sure if this supposed to work like this because it could be intended, I never played PE edition and also there are other future items that show up in either Survival or creative but not the other one.