Stores auto-duplicate after a while

Hello,

I import stores by uploading a CSV file. First, I delete all current stores. Then I import the new CSV and eventually I click on “Fetch Missing Coordinates” to fill missing coordinates.

Everything looks fine, but after a while the stores duplicate, and I have to manually delete (half of) them. As we have almost 1000 stores, it’s quite annoying.

I don’t really understand why this happens and how to avoid it.