How do I set a random sprite size with sine behavior?

I have a sprite that spawn with random size. but I want to put sine in it.. and when I do this, the sprite spawn with the default size... it is a bug?

Works fine when i try it.

Works fine when i try it.

I discovered the error... is with the 'size' sine.

How can I fix that?

Thanks

Ahh, I see what you mean and you're right, it does change to the default size before the sine take effect.