OnTriggerEnter not called on enabled for colliders inside

When we enable a force field Collider, I want all the colliders inside of field to OnTriggerEnter. Nothing is happening. OnTriggerStay is not called either. OnTriggerEnter works if we move a a Collider into the field.

Solution: We added a Rigidbody to the force field Collider. We now get an Enter and Stay when the force field collider is enabled. Made it Kinematic