Same problem here. However when I close the app and then start DJI Go 4 while the drone is in the air I can manover the drone beyond the limits. In my case 30m altitude and 50m radius.
Afterwards Litchi can be started again and it will continue to fly beyond those limits. Not very useful this behaviour.
Another idea would be to take off without the app running and starting it as soon as the drone is outside the limits.
I already tired to remove and reinstall the app - didn't help. I'm on iOS.