My foliage actors are tripping/spacing/doing weird things, when pressing play

I downloaded some foliage actors in the store, but when I press play they are doing some weird things. How can I solve this?
I added a link from the video, because I can’t upload the video as a new user.

Hi Charlotte

It’s a little hard to Diagnose from the video. My guess is this is something to do with the material, usually these are animated by using the world offset position node. What is strange is that it only doing it when your playing the game.

It look a little like you have scaled up the grass to a massive amount and are very close. Therefore the small swaying that you would usually have is magnified to be massive. Try disconnecting the World Offset position node on the material and they should stop moving.