Happy ghasts don't have effects when mounted

I thought the happy ghast was a bit slow when mounted so I used the effect command(/effect (at sign)e[type=happy_ghast] speed infinite 4 true) to give it a speed boost, yet when mounted it didn't change its speed, despite entering the command correctly and multiple times, it didn't have any sort of change in speed, yet when I dismounted it it zoomed around which meant it has the effect just not when mounted