Entity ridden by axolotl will move very slow

When you spawn axolotl riding some entity (for example cow), entity ridden by axolotl will be very slow. Interestingly, when entity is following something (for example when you use wheat on cow), entity will move normally.

How to reproduce

1. Type

   /summon cow ~ ~ ~ {Passengers:[{id:axolotl}]}

2. Observe