Did you have any exterior work done (tinting, etc) that they might be able to smell? Another possibility is if the car "wakes up" during the night to charge, for instance, that could startle them and make no sense to them either - that turns the car from an object into a "live" being. Both are things you can overcome, with training and perhaps an anti-anxiety supplement like Adaptil (I don't have affiliation with the company, but it's helped my dog in the past with anxiety over my new computer - so talk to your vet).
This is my bet... I have some security cameras in my garage, and I noticed that sometimes the IR on my cameras I think triggers sentry mode on my car, and sometimes the car will flash and record a clip for no apparent reason... Once it happens it starts a storm, because the headlights flashing causes my camera to turn off IR, then it gets dark, and the IR turns back on, and the dance continues... Usually for a few minutes, then it settles back down like nothing happened...
YEah, I could turn off sentry mode, but I'd rather keep it on, since it's plugged in anyways. When I turn it off, and the car goes to sleep, sometimes i get an issue where the app fails to wake the car when I need to do something... Also, I'd rather not encounter the issue where a dead 12v battery screws me... If you keep sentry on, the car won't go to sleep, so the HV system won't turn off, so a dead 12v won't screw you... (The issue if you have a bad 12v, is that once the system goes to sleep, the HV system turns off. But if you have a bad 12v, it won't have enough juice to turn the HV system back on, so the car will be "dead" until you replace the 12v. Sometimes it won't be dead enough to let you open the frunk with the jumper in the front tho.. But anyways, this is why when you get a warning, it says the car might not start again, becuase the car is saying a low 12v system might not be able to turn on the HV system if it turns off. If you leave sentry mode on, the HV system stays on, so the car will always be "drivable". The DC-DC converter will supply 12v, even if the 12v battery failed in this scenario.)