Hi! I was able to solve this issue. Actually it was my mistake to use the same field AffiliateURL both in “Update Key” and “Fields” inputs. In “Update Key” you should put some other field in your database. Then, in “Fields” you pass the corresponding inputs that will be changed in the database.
Explanation: as you can see in my example above, I had only AffiliateURL in both fields. MongoDB Node was trying to find that value in the collections in the AffiliateURL property, but I was passing the already updated one, so it would never work. I had to put another field in Update Key (in my case, I had put “productName”, which wasn’t going to be updated), then it will work fine.