Setting morph target makes mesh flicker madly

So I followed tesla’s instructions here: Unreal Engine 4 Tutorial - Morph Targets (Blender) - YouTube

I made a subdivided plane that simply raises a hill in the middle. I imported the mesh as skeletal and tried to test the morph target in persona. When I changed its value, the mesh was flickering like mad. Even when not changing the value, it flickered from the morphed state to the default state at random whenever the morph target was set to anything but 0. When I used a timeline in the level blueprint to animate this, like tesla did in his video, the same thing happens.

Curious thing is if I simulate rather than play, and keep the mesh selected, it does not flicker. It animations smoothly as long as the object is selected. When unselected, it continues flickering.

Why is this?

I have exactly the same problem and I’m using the latest version 4.13… :frowning:
The geometry is a simple plane subdivided along one axis few times, and zero subdivisions in the other.
If I set the weight to negative values, I do not get the flickering… and if I add some thickness (extrude the border of the plane) to the geometry, I don’t get the flickering…