So, following along from this Reddit thread…
https://www.reddit.com/r/unrealengine/comments/zoitm0/trees_make_weird_stretching_up_and_down_movement/
The guy gave the answer to this problem. All credit goes to “Ace_BlazeX”.
Since the update this June, its reappeared.
Now, his fix is not working anymore, since they have changed the underlying code and have compartmentalized more things into a material function.
Technically, the fix is the same, but just in a slightly different location.
Original method…
Search for the Material MF_Simple Wind. In the Main Rotator -Comment double Click ObjectPivotPoint . Change the Transform Position Node to:
Source = Instance & Particle Space
Destination = Absolute World Space
New method…
Search for the Material MF_Simple Wind. In the Main Rotator
Highlight the ObjectPivotPoint
Select the new material function ObjectPivotPoint to go to the new function.
Select the top node & change…
Source = from Local Space to Instance & Particle Space
Everything else stays the same.