AP braking due to steep elevation change

[2021 M3P]

Does anyone's car engage the brakes at a steep decline?

I just got my M3 Performance with only a few miles on AP so not sure if this is to be expected. There was a steep elevation change on the freeway and the car slammed on the brakes for a split second. It startled my passenger awake and I'm sure the car tailgating me was also surprised.

Is this normal?

 

[chazzzle]

The term we use for this is “phantom braking.” It can happen at any time, for seemingly no reason. I mostly notice it randomly on underpasses, once a month or so, sometimes less.