Dealer said they’ve never heard of this

My 2011 Cadillac SRX was purchased by me from
a dealership in December of 2020. In the 3 months
I’ve had it this problem has happened about 6-7
times: when I turn my car off (push to start with a
FOB) and get out and walk away about 20 feet’s
distance, the car will TURN ON ON ITS OWN! I DO
NOT HAVE REMOTE STARTER  and sometimes it
happens multiple times. Like I will go back, turn it
off, walk away again and it’ll just turn back on.
Frankly it’s very annoying esp in the cold weather.
Plus I’m constantly having anxiety that my car will
just turn on in the middle of the night and run for
hours! Am I driving a Christine? HELP no mechanic
I’ve spoken to has ever heard of this and apparently
neither has the internet!!!