The RTH function is probably one of the most over used functions on any DJI Drone. If you have line of sight on you Mavic, you should be able to watch how it moves with the control sticks and still bring it home with no problem. If the camera is working, then that is even easier to make it come home. Your compass on the screen will tell the direction it is facing relative to where you are. I learned the hard way when it came to bringing a Phantom home, it was with a Phantom 2 and a GoPro camera, which requires a BlackPearl Video Monitor and even more ways for you to loose control. I got scared as ****, the Phantom was quite a ways off and I was scared that I was just making it go further away. I finally got hold of myself and then slowly moved the stick one way or another and finally got it to increase in size. So was able to bring it home. This was before I found out that the diamond in the screen meant my location. Most if not all loss of Drones is pilot error. But most would prefer to lay blame elsewhere. Yes, I had my
P2 take off and go like a bat out **** more than once but was able hold the control stick down and got it to make a real hard landing, normally just busting some props. Then I learned about IMU calibration and how important it is. You should always recalibrate your IMU after any firmware update, no matter which model of drone, the be sure you calibrate you compass to any new flying location.