Modifier in FBX from Blender behaving odly

I am using a modifier animation in Blender to reveal an object, in this case a brain. The animation works until I am above the object and then the image pops to the final frame.

Has anyone dealt with this and if so do you have a solution?

Here is the test project:

https://playcanvas.com/project/568931/overview/wave-brain

@anon49240888 the link you attached is not working, could you please repost?