special relativity - what about doing the laser beam in a moving reference frame but with a ball

I realize the situation where a laser beam moves vertically in a moving vehicle

but what if the laser beam was a normal ball If we do the same steps of the proof considering that the velocity of the ball is not absolute and will have different velocities in different reference frames there will be no time dilation what is wrong in my understanding because according to special relativity there should be time dilation whether the event is a laser beam bouncing or a ball.