Arrival SoC buggy

Hi there I set arrival SoC to 30% but the planner keeps taking me down to 9% for arrival at my destination which is ridiculously low. I’ve definitely set destination and charger SoC to 30% but nothing has changed when I clear and start planning again several times. I’m a new user so this isn’t a helpful start!! I know there are more chargers on the way to where I want to go that aren’t being used. Any suggestions? I’m going from Norwood in SA to Mildura Vic. Thanks!