Minis are very intelligent but motivated by fun. Mine is very velcro but still struggled with recall. The reason is they are smart enough to know that recall often means the leash goes on, and even of you practice without that, they can tell when leash is on your mind. 9 months is very young. At that age mine was wonderful about staying near me but was always cautious about staying out of reach if he thought it was time to go home. I worked on this by eliminating his ability to blow me off. I had him drag a biothane line constantly. Even in the house. After a while he stopped trying to get out of my reach. I worked constantly on rewarding him being by my side. Any time they come to you, give small rewards whether you asked for it or not. Try not to ask for a recall if you will just put a leash on. That makes a bad association. I always attracted with other ways if I needed to leash. Over the process of many months, you should see improvement. Maturity and training brings more biddability and less fooling around. My dog now comes to me and stays by me when he feels it is time to go home... usually. I also frequently attach his leash for a moment then unattach and release. Don't expect immediate results from anything. Think about improvement over 6 months of working on it.
Lastly, I strongly suggest a whistle conditioned with a very high value treat like a large chunk of roast chicken. Use chicken for the whistle for at least a month before phasing out slowly to normal treat rewards. Whistles are more easily heard by distracted dogs and the sound carries further. A mini titanium whistle is ideal. Train a verbal recall as well, but I like the whistle for the success it brings.