My issue is that the collision matrix I think is bugged as I tested the same thing on a different project and the same thing happened, it seems like triggers need to collide with solid otherwise they don't trigger. Here is the scenario, I have two spheres the white sphere has a trigger-receiver tag, the red sphere has a trigger-source tag. Here is my current collision matrix, things should collide when I test it in game: And it does (it prints it out in the console log): I'm now going to just change one thing, and make it so that the two tags can't collide with a solid tag: So now, all I've done is said ignore anything that is a solid tag, and will test it out in game (for some reason, no collision triggers) No collisions, doesn't show it in the console log. I tested it on another clean project it actually has the same issue.