I had read similar issues. Read some solutions like this oneMavic Pro: ISO and focus issue
I flew my first DD mission few days ago. I planned my flight at 250’ agl, so before I opened DD app I flew up to 250’, and used the tap to focus, then changed camera to manual and landed. Never shut the drone off, just turned controller off and back on and went to DD app and flew without any issues. Had good images and made a decent maps.