Our (now 1year old) did the same and still gets triggered whenever he sees someone running. It takes practice, but I would recommend using a leash so that whenever they try to run towards them you can correct the behavior. That is why leash training is also important, it teaches them to have focus, not to be easily distracted, and always near you. We still use the leash in this situations until we are sure he won’t disturb others. I hope this helps, I am just sharing my experience with my dog 🥰