No but people have had other menu options disappear. Make a note of your current settings then delete the App, reboot the device and reinstall the App. That typically works.
I could be wrong but the "display radar" is at default ON (enabled) position only whilst "Obstacle avoidance" (the option above the radar) is enabled. This is necessary when u fly in OA.
If u where to turn OA off then the radar toggle becomes active and you can turn it off.