chickens stuck when lead through water

Put the summary of the bug you're having here

What I expected to happen was...:
chickens to swim across water without holdup for grasses

What actually happened was...:
when chicken swam on block with grass in it it stopped and spun in circles

Steps to Reproduce:
1. lead a chicken with seeds
2. lead it into water
3. lead it over a block of water with grass INSIDE (not below) the block of water