Trouble Painting Foliage

Hi all, I have search a lot about foliages, but I cant find a solution or a clear answer for my issue.

I’m trying to paint some foliages in the hollow of a cave. The object is a static mesh and is concave and I think this is the mayor problem in my case.

This is my mesh

And here you can see I have some meshes config as foliage

But when I try to paint this meshes I can’t paint it at all.

Do someone have any advice for me?
Thank you and cheers.

I’m thinking its most definitely because its concave, although I gotta ask, is stuff like collision enabled on it?

Try building a cave out of convex rock objects instead?

In the sceenshot collision is disable, but I have try it before with the tick enable and collision complexity as simple collision as complex and the collision preset as block all, but the result is the same.

There are more things that need to be enabled or disabled?

Saddly I can’t rebuild the cave, this project is a port of an amateur project I do with other people with a custom engine coded in C++ and the challenge is transfer the hole project into the UE4

I have done another test with another foliage over another mesh, now convex, but the result was very dissapointing.

I need to put the camera quite a lot far from the mesh to see the white brush. If the brush dont appear I can’t paint.
And after paint, look at where the foliage are placed. The official tutorials don’t talk about all this issues and I don’t know which could be the problem.

Anybody could help me, please?

can you paint foliage on other BSP, static meshes, terrain?