New ones won't engage till 25mph and automatically disengage below 25.
Still like I said even with the unit on it won't shift unless you push the button to tell it to shift. I would just shut it off and try without it.
Cool wasn’t sure how they worked now a days. It’s been years since I’ve been in a car with one, at one point, they were electric activated with a switch but again, that’s been nearly 20 years go .