Two questions, Luca.
1. When you found the duplicates, dogs you take a look at them in the text editor?
2. And, i remember when i had this particular issue myself, i believe that i found the ones that were getting priority in the roaming or application support folders. Don't want to send you down another rabbit hole, and I will look through my old emails to see if I have Exact Solutions. Just know that you're not alone.