I too used to have to go back and forth between the DJI Go app and Autopilot. I also used to have the focus issues when starting a mission. Ever since they put in the focus feature on the camera view page, that's been fixed. Maybe I accidentally clicked off dynamic focus one day. Maybe it happened during the most recent app update. I don't know.
I do think that Autopilot is getting a bit of hard run here from some folks. To be fair to those frustrated, I understand your pain. There are a TON of options and the layout takes some getting used to. I got frustrated many times. It took me FOREVER to find the button that allows for camera changes in the app and the button is so small that I have hard time pressing it to get to my camera settings. It would also be nice to have a button on screen that quickly goes back and forth between inline controls and hide inline controls, but I digress....
In my opinion, Autopilot is by far and away the most powerful tool I've ever used on any UAV. Nothing else I've ever used comes close. The tutorial videos are long and they take multiple viewings. The terminology gets confusing as some things don't have terms I would expect while other settings have terms to similar to each other which makes it easy to confuse them, and lastly, it is going to take a long time before you get "quick" on screen with the app (like you see the designers during their videos). It took me roughly 10 hours of total flight time before the app became second nature to me.
HOWEVER, once you get to that point (and it is painful to get there), it is truly the greatest tool and I applaud the designers for working hard to constantly make it more user friendly - Let alone constantly add more and more useful features for free. It's amazing. For me, it completely negates the need for a two pilot system. I would dare say it is better because as a single operator, I know exactly where my Inspire is going. I can think ahead of time how I'm going to move my camera with the stick as opposed to missing a shot where a pilot makes a move with the drone that I was not expecting. In addition, I cannot get good, stable footage when flying with a 25mm lens or longer when simply flying and pointing the camera. I can however get amazing footage by simply setting up a flight path with autopilot and then carefully controlling the camera.
With the recent addition of Airspace a few months back, the possibilities are endless. I love the accuracy of elevation using the barometric pressure and being able to follow an iPhone while it changes elevation. It is brilliant. Seriously, for anyone considering putting in the time and effort to learn autopilot, it is worth it... but you do have to commit. I did it by setting up flight days where the only purpose of going out was to learn autopilot. That's it. Didn't take time to get any great video or pictures. I wanted to learn the program... then the good shots come along.