Transparency not working on imported models

Hello!
Recently I’m working on simple dungeon crawler with my custom made level generator. I decided to put a isometric camera and need to get rid of some walls which from time to time will be obscuring player character. I choose to keep my scripts as simple as I can so I went for simplest option like:

function OnTriggerEnter (other : Collider) {
	other.GetComponent.<Renderer>().material.color.a = 0.2;
	print("enter");
}

function OnTriggerStay (other : Collider) {
	other.GetComponent.<Renderer>().material.color.a = 0.2;
	print("stay");
}

function OnTriggerExit (other : Collider) {
	other.GetComponent.<Renderer>().material.color.a = 1.0;
	print("exit");

This script is attached to the camera with capsule collider stretched to line between camera and player character (camera has also attached rigid body to enable trigger work properly) and when I tested it on my playground project with simple GameObjects (cubes and spheres) everything was working perfectly. When I moved it to my main project and tried to make imported (FBX if that counts) wall models the script’s not working. I see logs on console only for one object, first that collides with capsule but even it is not nade transparent. No logs for next crossed objects.

Anyone has any idea how to fix it and get it working?

Does the shader in these objects support transparency?

Try changing the shader in the materials to one that does support transparency.

What about this setting on the material/shader
79588-render-mode.png