Hi anonymous user,
I confirmed with Product team and they are working on enhancing the documentation to explain the difference in total duration and working duration metrics for copy activity with examples. As mentioned, Total duration means the overall duration for each steps (in your screen shot, it has the queue duration and the transfer duration). and working duration doesn't include all components now which may lead to confusion. E.g. the serialization working duration is not included. Please do share specific activity run id, and we can further take a look to double confirm with the Product team.
Please suggest if this clarifies the question and hope to hear back with run ID from you.