Before flying in the circle mode you want to make sure there’s nothing to run into within your circle radius. You can use your phone to connect and make any adjustments from there. You must of had it set farher out than what you thought it would be . It would be easy to make that mistake if you weren’t use to how it worked yet. Also be mindful of tree branches or any wires. With practice it gets easier.
How was the light level? I used mine a few weeks ago to do some selfie shots in a relatively well lit area, and mine flew straight into an iron fence. Thank goodness it didn't get damaged.