Child collider does not trigger inside a parent collider

Hi I have 2 objects both with children which have child colliders. I want to have the collider of Object A (landmine) child of bombRadius to trigger when collided with Object B (humanFoot) child of human.

What is happening is when the human collides with the landmine, the humanFoot is not detected by the landmine. Only the parent (Human) is detected by the onTriggerEnter function.

I have read somewhere to add a rigidbody on my Object A (landmine), this sort of worked but the collision is only detected whenever I manually transform Object A (landmine) into the position of the Object B (humanFoot). When Object B (humanFoot) moves into the transform position of Object A (landmine) it still does not seem to detect the collision of one another.

Please help me. Thanks in advance.