I wouldn't worry about it, especially if the feedback you have is positive. I have tried to remind customers to let me know when they receive the package and sometimes I will get a convo but no feedback. I have about 1/3 feedback, and consider that pretty good. Many years ago I had a bridal business as a consultant and seamstress. I worked closely with my customers and their family and friends for many months. While working with some of the brides (we live in a college town) who were away from home, I was treated like an aunt and even invited to some of the weddings. Yet, after the wedding was over only a handful of times did I ever hear from the bride or her party again. Once if was over, they went on to new things.
Even though you might have several convos with a customer regarding an order, when they receive their items in good condition and being what they expected most people put the business part of the transaction and seller out of their minds. They have other things to deal with that become more important. Also, a large percentage of Etsy sellers are new to Etsy and don't understand about feedback.
On the other hand, when I send a convo to my international customers I do ask them to let me know when the package arrives so I will know they received it. Even then, half of the customers who respond do so with a convo and not feedback.
