This is probably uncommon.
Wondering if anyone knows if this is actually a security feature?

My garage is narrow on the right side, and it is hard if not impossible to get out on the passenger side when parked on the right side.
Wifey has the left side which is bigger.
I was procrastinating changing to winter tires.
And it was snowing pretty hard this morning when I did them so I did it inside the garage and needed to back in to the garage to do the passenger side.

So I was crawling through the passenger door to enter and exit. (I took my shoes off )
After finishing my wheels, I tried to start the car and it had locked itself and set off the alarm.
I unlocked the car with my activity key (which I use as my car key nearly all the time) to stop the alarm.
I started it and went to the store, when my car warmed up and did an auto stop, it shut off and armed the alarm again and I set it off trying to start back up, thankfully no one was around me.
Side note: my auto stop/start is so unobtrusive I only turn it off sometimes when I know I will be in traffic. It has worked flawlessly, since I got it in April.
I had to unlock with my key and start again, switched off auto stop, and got to the store.
As soon as I turned off the car it locked and armed again and when I opened the drivers side door the alarm sounded.
Had to used my key to turn off the alarm again, this was the first time I opened the drivers side door since putting it into the garage.
I closed the driver door and used passive entry button to lock the car, at this time I was thinking battery, pivi screw up, some sort of electrical problem...
I was getting ready to call my wife to pick me up if the car wouldn't start or took a turn for the worse.

I went to get my stuff, came out and got in normally, everything was fine, entering was ok, start/stop was fine, parking in my driveway was fine.
Went out one more time and then parked back in the garage, everything was ok.
Then I realized I did get in the car in a weird way earlier and the driver door not cycling could possibly trigger a security mode?
Anyone know if this is true?