Intersecting edge colliders cause particles to pass through one edge collider?

I’m working on a game where sand falls onto edge colliders. The particles are passing through edge colliders when this should not happen.

I created a simple example by creating two edge collider objects, which form an “X” by crossing, in a blank 2D project. I set up a particle system to release particles with a box shape - “Sprites-Default” material. I ticked collisions to be on and turned off bounciness. The collision is set to “2D” and I scaled down the max particle size along with radius scale to an appropriate size so it looks like small squares. If you allow the particles to fall onto the side of the X, they will pass right through one of the two edge colliders consistently. Sometimes they don’t. It’s very inconsistent no matter what I do, and I can’t for the life of me tell understand why they will slide right through the intersecting edge colliders and not just stay trapped between the two.

Hey. I had a very similar problem with some particles passing through right edge of the square “box” made from edge colliders. In my opinion it was very suspicious that particles pass only one particular VERTICAL edge and only when move in one particular direction (which is from the left of collider to its right, and what, in my opinion, makes it the same situation with yours), so I’ve sent a bug report and this is the answer from the Unity QA dude:

"Thanks for submitting a report!

However, I don’t think this is a bug.

On one hand, in your Particle System
Collision Module you have World
Collision, which states in the manual:
“This is an approximation, so some
missed collisions might occur. You can
reduce the Voxel Size value to help
with this; however, doing so uses
extra memory, and is less efficient.”
Unity - Manual: Collision module

On the other hand, Edge colliders can
sometimes be inaccurate as well. You
could try increasing their radius, or
using box colliders for the same

So it’s not a bug but the feature!