Recently updated mine and never seen this issue. Only time mine ever does that is when the battery drops to 19% (I think).
Always fly in line of sight so never even seen the out of range return to home.
I wouldn't do any firmware change unless absolutely necessary. Best to do an IMU calibration any time your flights turn wonky/abnormal..instructions in the FLY app.That usually cures what ails ya.
As long as the ARB number hasn't been increased by DJI: yes, it is pretty straightforward. All you have to do is download DJI Assistant 2 from the official DJI website and install it to your PC. You launch Assistant 2, then connect your drone to...