Minecarts get stuck in water currents

When minecarts jump into a stream of bubbles, they slow down until they come to a standstill.

 

Steps to Reproduce:
1. Build a structure with rails for the minecart to jump on.
2. In the place where the minecart falls, place soul sand and water to create a water stream.
3. Make the minecart jump into the water.

Observed Results:
The minecart remains still, floating in the water.

Expected Results:
The minecart jumps with the water and continues its straight path.