Bats move even though they have a 252 slowness effect and a base speed of 0.00001

Bats spawned using the /summon command with slowness and speed attributes of 0.00001 will still continue to move at a normal speed

What I expected to happen was...:
Bats that would not move and stay in the air

What actually happened was...:
Bats that flew at a seemingly normal speed

Steps to Reproduce:
1. Execute the command summon Bat ~ ~2 ~ {Attributes:[{Name:generic.movementSpeed,Base:0.00001}],ActiveEffects:[{Id:2,Amplifier:252,Duration:10000000}]}
2. The bat will move at normal speed