alarm keeps going off 2015 taurus limited
 

I have brought it to the dealer who did not find an electronic problem in diagnostics. Alarm and then flashing lights goes off a few minutes after I leave the car.
I have tried closing trunk and hood. I thought for awhile it was more likely if I used the key to lock, but that has proven not to matter. I have heard that it might be related to a problem with the manual lock, so I have tried putting in my key and turning it back and forth a few times. Tried this intervention many times. Sometimes I think it helps. It may or may not be related to colder whether. Not sure.
I would be perfectly happy finding the fuse and taking it out - just disabling it - but even the dealer wasn't sure which fuse it would be.
A month or so ago I found out I had a dead old battery. That has been replaced. Did not solve the problem. There is a spot in the fuse box that could have some battery acid damage. Have cleaned it. The fuses in that small area do not appear related.
PS - many online solutions talk about using the key in the ignition instead of auto start to reset. To my knowledge there is no key ignition anywhere in this car. Would be glad to be wrong, but I sure don't see one. 20015 Ford Taurus Limited.
I have also changed the battery in my key fob.

Possible solutions to stop the alarm? Any idea which fuse could disable it without damaging other necessary features?
Thank you.

If you can, consider trying a different dealership service dept.

There could be a few reasons as to why they couldn't determine what is causing the problem.
Some placed have more experienced service people than others.

What do you think ?