Happy Ghast is not affected with Attributes commands

Happy Ghast is not affected with Attributes commands specifically the movement_speed and fly_speed attibutes. although the numbers on attributes are stored but it does'nt seems to change its movement/fly speed.

Procedure:

1. Summon Happy Ghast using spawn egg

2. Appy attribute /attribute @n[type=minecraft:happy_ghast] minecraft:flying_speed base set 3000 and /attribute @n[type=minecraft:happy_ghast] minecraft:movement_speed base set 3000

3. Observe its fly speed

4. put a harness to a happy ghast

5. mount and drive the happy ghast