Weird physics behavior with custom collision mesh

I’m getting weird physics behavior on static meshes with imported collision meshes.

Here’s what the collision mesh looks like (in blender):

There’s extra geometry at the ends because I made it protrude from the top very slightly just to make sure it was convex, in case that was causing an issue, but it didn’t change anything.

Here’s what the collision looks like in UE4:

And here’s a video of the behavior (at half speed): [ue4 collision issue - YouTube][3]

What is causing this behavior and how do I prevent it?

Found a solution to this problem. Apparently it’s because of UE4’s buggy support for PhysX PCM. Disabling PCM under Project Settings > Physics > Simulation > Enable PCM seems to fix the weird behavior.