Can I change wind affecting a speedtree at runtime?

I have a wind actor in the level, and when I change its value in editor it works fine and affects speedtrees as expected.
I’m trying to change wind values using the level blueprint,
I currently have a reference to the wind actor, I then get its directional wind component, and change speed and strength at runtime using “set speed” and “set strength” nodes, but nothing seems to happen.
any ideas? or is it actually possible to change wind at runtime?
I’m using version 4.4.3 and using the Broadleaf_Desktop sample tree.

I managed to get around the issue by multiplying the speedtree node going into world position offset in the material with a collection parameter, then I’m able to manipulate that using blueprints at run-time.