Still happening in 19w04a
I think it's not just taking longer to update, but it's not update at all, at least that's what is happening in my case.
It also happens when pressing backward while leaning against a block
I"ve noticed they stack into 9 items instead of 16 (inside and outside the chests)
Same thing happened to me just now.
Sure it's just a snapshot, but I think it as a little recklessness to not test it before launching. Like someone else said above, with five minutes of gameplay it's possible to observe those bugs and fix it and avoiding headaches. Maybe they're lacking of people and time, but it's getting annoying to see avoidable bug in every new snapshot. Only if those bugs were minor ones, but they are not.
Well, but the new features are really nice though. Keep on the excellent work, Mojang, but, please, try to be more prudent.