Hopper Cart stops when floor above moves

As it says in Summary, while a hopper cart is moving along tracks(1 high area), if the blocks above move then the cart stops.

I have a flower farm where the Hopper cart moves in a 1 block high area picking up seeds and flowers from the floor above. The floor above moves back and forward very quickly while it gets bone meal. In this update (haven't tried the others) as soon as the floor moves the carts stop, meaning having to rip out the floor above to move the carts again.

Is this a bug or is it meant to be in the game from now on?