Hi @kevinl3 ,
I think this usually happens when the app’s webhook does not receive Make’s webhook response like the webhook has been received in a timely manner. There are some apps that have a very short “patience” when waiting for the response so what happened here is that Square’s webhook is a bit impatient and thinks it’s not received thus resending the webhook data again and this is causing a duplicate.
I had this issue before yet adding Data Store modules is a huge help when it comes to this kind of case!
https://www.make.com/en/help/tools/data-store
Hope this works for you!