Steps to reproduce

1. Create a pool of water several blocks wide. Make the pool at least 2 water source blocks deep because of MCPE-122278. Use full height blocks (e.g. sand, grass, dirt, or clay) around the edge of the water because of MCPE-165109.
2. Spawn several dolphins about 10 blocks away from the pool.

Expected result

Within a few seconds the dolphins start crawling toward the water.

Observed result

The dolphins constantly bounce in random directions. They occasionally bounce in the direction of the water 3-4 times in a row but then move in a random direction again. Some may land in the water by chance while others drift away from the water and dry out and die over time.