I have no idea if this will help but this is what I did with my mare when she decided, all of a sudden, to be stubborn on the one rein lunging where she would just face me/stay close to me/back away from me when I tried to get her to move on. I put my arm out (I had a lunge line attached but it could work without one) in the direction I wanted her to go - gesturing with the lunge line but not pulling her at all. And then I began to walk towards her, flicking the lunge whip (I didn't crack it as my horse is terrified of that sound). At first she started backing up and looking a bit nervous but I kept at it, approaching and flicking the whip while gesturing where I want her to go and eventually she began to move forward. The moment she did I released the pressure and let her go. It took about 3 times for her to get it and since then she doesnt have a problem going around in that direction anyway. The trick is to keep 'up-ing' the pressure until she moves and to keep calm, even if she does get a little nervous, she'll soon learn that if she moves forward, the thing she's scared of moves away.