Not sure what exactly what you're looking for, or expecting, here.
You and your team are going to need to do a much deeper analysis of what's happening.
Electrically make sure your circuit is not exceeding the absolute maximums called out in the data sheet.
If your code writes/changes flash, you might want to examine that more critically, adding sanity checking and looking for earlier signs of failure to reduce the detection time from 10 days.
