Detect Collision between an Instantiated Object and a non Convex mesh collider?

I made this question very specific since OnTrigger and OnCollision Functions are not working. Basically I have a cube that spawns at a random area within the game play field I'm trying to check the area it exists at and make sure it's valid for the actual player to spawn there and if not the cube would respawn and check a new area.

I know basic unity logic which is why I tried OnTrigger and OnCollision functions but Is there something special that needs to happen for instantiated object and non convex mesh colliders?

I also used the procedural cave generation code from the unity tutorial for my project unfortunately they just made their player spawn at the same point everytime. If you would like to see the scene and object's inspector let me know :)