Sometimes Actors with Destructible Meshes fall through Landscape

In our map we have a landscape, which has collision (query and physics) enabled and every channel set to block. Then in the game the player can throw (grenade) actors, also with physics enabled. The have a destructible mesh as root component, and on hitting the landscape they fire an event (exploding, damage, etc.)

This works fine in 99.9% of all cases. However, in very few situations those grenade actors don’t collide with the landscape, they just fall through it, the hit event is not triggered. Since it’s the same actor which works most of the time but only in a few times it doesn’t, I don’t think it’s that actor that causes the problem, but rather the landscape.

I do have enabled CCD for the grenade actor, which seems to have improved the situation a bit, but the problem still occurs in a few cases. Also enabling physics sub-stepping did not help.

Any ideas what else I could try?

I’ve seen this happen with ragdoll too, but that seemed to be a matter of speed. Not sure it’s the same, but could be related