Here is today’s comic.
To clarify yes I know he was able to sniff Longstar and Silverfang out in the beginning chapter but being aware of people using scent and animals is different. Plus given he wasn’t in the forest surrounded by similar scents to those he would find on the chimera living there means he didn’t have to focus on differentiating the scents from the actual forest around him or try to check if they were moving, somthing he is being taught is to see if they scents on a person or animal and not part of his surroundings as well has focusing on the subtle scents that differentiate it from the more static environment.