Nvidia Hairworks/UE4 in game problem

I’m having a problem with UE4 and Hairworks for sometime now.
Both in FurViewer and AnimBP, the hair move realistically with my character.
When I try it in game though, the hair move slowly as if they have less gravity.
What I mean is that they stay more time in air and they follow slowly my character’s animations.
Is there an option somewhere or is this common with UE4 and Nvidia Hairworks?

Thanks in advance.