Alarm problem

My car alarm keeps going off for no apparent reason.

I have been through so many of the threads on this site addressing problem alarms. None of them seem to really apply to my situation.

I have a 2018 Prius Prime Advanced
I had it at the Toyota dealer service department last week. They checked the car battery, replaced the fob batteries, and did a once over of the entire car. They then reassured me that there was nothing they could find wrong.
Additionally...
Following additional instructions on other threads here: I've located and cleaned off the hood sensor. When that didn't help I tried cleaning every sensor I could find. I've tried bumping the car different ways to set off the alarm. I've tried leaving the doors unlocked and still had the alarm go off while the car was parked.

The only thing I have found seems to be consistent is that it only goes off while parked in direct sunlight. I live in Texas and the weather during the day has hit triple digits the past few weeks. I can't find anything online about heat affecting car alarms but that is the only thing I haven't been able to correct for at this point.

Does anyone have any other information? Could it be the heat? If so... is there anything I can do?

 

It's the alarm that was in the car brand new. Not installed separately.

It happens daily. Whenever I park in the sun in the afternoon.

I've tried leaving my fob at home and taking my husband's fob. It still happens. I've changed the batteries in both fobs and it still happens.

Are you suggesting I pull out the batteries every time I turn off the car? Willing to try anything.

But it still seems that the only common denominator is parking in the sun when it's hot in the afternoon. Unfortunately, this is an unavoidable situation for me. Or I might just never park in the sun...

 

It's not aftermarket

Also I've had the car for a year and it didn't start doing this until the last couple months

 

Rodents?

 

I thought of another possibility. I've noticed that it seems to happen at the same 2 places weekl . I thought it was due to parking in the sun primarily because I couldn't think of any other difference between those places I parked in and any other except the direct sun.

Been doing more research to find a solution and found information about other people's fobs setting off alarms in neighboring cars. Has anyone else run into that? Is it possible to change those settings in a car alarm?