Interior light stuck on somewhere? Like in the boot? As I remember the battery saver could kick off the alarm if a light was on due to the load change.

Or possibly volumetric triggered as the car warms up in the day? Have an idea this could be from the boot vents not working correctly.

Though it's a long time since I had one so not 100% sure - got through 3 of the things so I saw most things at one time or another.