Sounds like a perfectly normal puppy. I agree with your trainer, use a higher value treat (maybe something just slightly better than the kibble- but most puppies won’t give you the time of day outside without something very delicious), keep sessions very short and spread far apart (like 30 seconds- 3 minutes every 3 hours for example), and most importantly bond with your puppy through observing them without pressuring them and playing (try to teach them to enjoy toys, it will help you immensely with training). I really wouldn’t do much training on a walk or expect a baby to pay attention to me. In fact I don’t think I would be walking a 9 week old at all, since they’re not protected against parvo. If that wasn’ta factor though, I would put them on a harness and long lead and let them explore and learn to be comfortable outside. Meanwhile watch them, be very patient, when they look at you or walk back to you WITHOUT prompting, throw a party and rain treats on them, then leave them alone again and let them explore. Over time this is whats going to build that attention span and value for paying attention to you. During the day too, if you catch your puppy looking at you say “YES!!” and give them a cookie. Do this all the time and you’ll have a dog that never takes their eyes off you lol.