Hi, I got a Captiva, trying to get my trans temp right so I can drain it properly.

I followed a guy who was doing a tutorial on how to do a trans fluid change on a holden cruze, same trans, he and the manaual say that it needs to be 85-92’C to check oil level etc, i drive the crap out of my car with the app showing nothing over 81’c, im talking driving up and down a mountain! i dont know if its the app? it does read and change perfectly during driving, but averages at 71’C