When I run my app in the prototype it captures the track name and ends the session. Here is my code and voiceflow diagram. @ashwin.salgaocar kindly check it.
As shown in the video ,they have created a variable top 5 artist and given the limit of 5, in your screen shot you have taken top 10 artists so please check that if you have created the correct variable and given the correct limit. Also check if you have used the correct variable in the first code block.