I was working on a PEZ Dispenser for a rail station of mine,
and was shocked to discover that my original design would not work.
The minecarts, after being placed, phased into the same 1x1 block space
rather than stacking on top of eachother.
This has not been so in the past, so I would like to bring attention
to this issue.

What I expected to happen was...
The carts would stack on top of eachother

What actually happened was...
The carts all moved into the same space

To Reproduce:
1. Set up a rail so that a cart pushed on it will fall off a cliff, onto another rail.
2. Push multiple carts off the cliff.
3. Observe as the carts phase into the same 1x1 space rather than stacking