Can't edit transform after enabling gravity on rigidbody

So, I’m just starting out with Unity and watched some tutorials on collision detection.
What I’m trying to do is make a monster move towards a trigger box, when hit the trigger box will be repositioned inside a pre-defined area and then the monster will move to the boxes the location.

I added a rigidbody and a box collider to both. my trigger box has no gravity and is kinematic (IsTrigger is checked). The monster has gravity and is not kinematic.

The Problem: Ever since I checked “Use Gravity” on the monster I cannot change the position of it via Code.
What do?

How are you changing the position in code?

Typically if you are using physics on an object you’ll want to move it using the object’s Rigidbody rather than its transform. However I’d expect the consequence of not doing that would be for it to be moving slightly slower and more erratically, not for it to not move at all. Still, it might resolve it, and would be a good change regardless.

So I changed my code to use the transform of the rigidbody now. no change.

this.GetComponent<Rigidbody>().transform.Translate(this.transform.forward * this.movementSpeed * Time.deltaTime);
//this.transform.Translate(this.transform.forward * this.movementSpeed * Time.deltaTime);

OK. I figured it out. the issue was not the moving itself but the way the monster entered the state of “MOVING”.
At the very least I now know that moving the rigidbody instead of the gameobject is a best practice.