I have attached an image of my dji smart controller screen while the drone is on the ground but running. I can't find out what the red curve means. If i take off it is still visible. It is accompanied with a beeping from the controller. Can Someone please help me? I'm new at this.
Thank you.

Proximity warning. If you are well away from an obstacle it is likely that you have something on the aircraft that is blocking the rear sensor  on that side.