Has any one had this problem I have 2017 xc60 t6 on a very slight slope the car rolls back when in park this has happened 2 times????? update today it seems to be okay.

 

Put the vehicle in park then set the parking brake.

 

I took it the dealer Tuesday they drove it parked it on a hill it did not move,also it the last week it has been parked on a slight incline with no brake the dealer says there is nothing they can do unless it rolls on them.Thanks for all the sugestions.