Dakota Hawkins

What about Chest > Hopper > Chest? If you put a stack of items in do their counts go down while you have the chest open?

Edit:

Just tested in creative, that works. Also tested Chest > Hopper > Clocked Dropper, just in case, and that works too.

I tested in Win10 0.15.7: built 4 darkened spawn rooms with floors of half-slabs, glass, half-slabs+carpet, and glass+carpet. The only one to spawn anything was the room with half-slab floors, several hostile mobs spawned pretty quickly.

I'm having this same issue (but backwards), Win10 beta edition v0.15.6.

Chest > Hopper > Clocked Dropper Chain > Chest

Items placed in the chest don't disappear from the chest, but you can hear the clocks start on the droppers. So, you can remove the item, walk to the other chest, and collect the duplicate.