Jax lays on the grass

When he is out Jax loves laying on grass so we made a little lawn for him at home that was a few weeks ago and he has not been near it. Today he decided he likes it and lay on it for the first time. He is now 16 months old and has changed over the last few weeks getting much calmer he can still be an idiot puppy at times but generally he is much more chilled out. He walk well and doesnt pull on the lead as a rule and walks with a  loose lead even if he walks in front. He does if he get in front turn his ears back to listen to you. We are trying to get him out of the habit of lying down when he meets another dog as a pup it was ok as its shows submissive posterior but a few Staffies think it great to then attack him and it also frightens some dogs as he often jumps up very quick. So we are trying to make him sit quietly.