Definitely sounds abnormal. Are you sure you don’t have some sort of scheduled departure set (which should not go off when not plugged in (I assume - I don't use those crazy features), but could be a bug)?
Anyway
@AAKEE does not seem to have this bug.
Highly abnormal and certainly no reason for it at all - this behavior is not doing anything but hurting the battery, after all.
I'd just turn off every possible feature and see what happens. Your car should be asleep in 15-30 minutes. If it's not, it's screwed up. The preconditioning stuff (or something else) could cause it to wake up at some other time though.
12V monitor is useful for stuff like this if you have the 12V, because you can see exactly when it is sleeping.