Might a defective tow sensor cause alarm actuation? It would be rare but our cars are getting older.

The antitheft alarm is armed within approximately 10
seconds after locking the vehicle. A blinking light in the
tow away alarm switch indicates that the alarm is armed.
Once the alarm system has been armed, the exterior
vehicle lights will flash and an alarm will sound when a
door, the rear liftgate/decklid, the hood, or the glove
compartment is opened, or if someone attempts to raise
the vehicle for towing.