Front View Camera Setting Question

I want to be able to set my 2018 RX-350 so that, when the car is approaching a solid object at low speed, the front camera comes on automatically but (and here is the important part) the front camera never comes on automatically at any other time (such as when the vehicle's speed is 5mph or below).

When I first got the car, that's the way it was. Then, for some reason, the front camera stopped coming on automatically when I approached a solid object at slow speed. I guess I must have pressed the wrong button somewhere. Anyway, it stopped doing that.

So I contacted the tech person at my dealership. She said to put the car in drive and then punch the view button. This brings the camera up. Next, select "auto" in the lower left, which will cause the camera to come on automatically once again. I did that. The problem was that, then, the camera would come on automatically when I approached a solid object at slow speed, but it would also come on automatically every time I stopped the car at an intersection or anywhere else or the car's speed dropped below 5 mph. That, I didn't want.

So I got back to my tech lady and said how do I get it so the camera only comes on when approaching a solid object at slow speed but at no other time? She can't tell me.

So that's my question. What are the setting combinations to achieve what I am describing here? I know it can be done, because it did it before. How do I get it back there?