Changing Size Dynamicly, GPU Particles

I want to change the size of gpu particles dynamically with a parameter, trough blueprint.
This works for normal particles, but not for gpu particles.
Can you tell me why?

found the answer in a other thread:

Hi there,

An oddity of GPU sprites is that they require a “MaxSize” value which they take from the distribution. This can result in some seemingly odd behavior. If you set the Constant.x of your parameter distribution to >= to your max desired value then this should work fine.

Let me know if you have any problems.