Has anyone else experienced this:
You take off and test the "Fn", "Photo/Video" toggle, and "Shutter/Record" RC buttons and they all work. After several minutes you notice these buttons are no longer functioning but the gimbal wheel still works. You can, however, use the Fly app to control the functions assigned to the RC buttons.

I tried bringing the MA2 down and rebooting it, leaving the FLY app and RC running. This did not reset and allow the buttons to function. I then exited the Fly app, while the RC and MA2 were running, and started the Fly app again. Restarting the app corrected the non-functioning buttons situation and the buttons continued to function for the remainder of the flight.

I tried rebooting the Samsung Galaxy A71 prior to using the Fly app and this did not help.  

Phone: Samsung Galaxy A71, Android 10, April 2020 Security Patch

Hi Pappy3, we appreciate your feedback, it seems to relate to your mobile device, did you try to re-install the DJI Fly? Any chance to have a try with another mobile device in the recommended list (https://www.dji.com/mavic-air-2/downloads) for further tests?

DJI Mindy Posted at 5-26 03:27
Hi Pappy3, we appreciate your feedback, it seems to relate to your mobile device, did you try to re-install the DJI Fly? Any chance to have a try with another mobile device in the recommended list (https://www.dji.com/mavic-air-2/downloads) for further tests?

Sorry it took awhile, but the it's been raining the past 3-4 days and I wanted to fly the MA2 for a couple of days to see if this anomaly is still occuring. I did as you said, re-installing the Fly app, and the non-functioning buttons issue has not happened since. I'll update this post if it does. Thanks for your input.

Pappy3 Posted at 6-1 02:08
Sorry it took awhile, but the it's been raining the past 3-4 days and I wanted to fly the MA2 for a couple of days to see if this anomaly is still occuring. I did as you said, re-installing the Fly app, and the non-functioning buttons issue has not happened since. I'll update this post if it does. Thanks for your input.

this is a known issue of the app on exynos processors - if you switch off your bluetooth/turn airplane mode on(assuming your Bluetooth is on of course) will cause video/photo button stop working and also flight mode not switchable from the app. At least on the mini, on the air 2 might not be the case with the hardware button on the RC for changing flight mode...it has been in the app since day 1 and doubtful they will fix it. They cant put a fuc*ing black line on top of the app, i doubt they will manage to fix this kind of serious issues with their incompetent dev team. Workaround is to switch off bluetooth prior starting dji fly or if it happens to restart the app which renders 2 flight logs instead of 1.
here is a video for that issue:

https://forum.dji.com/forum.php?mod=redirect&goto=findpost&ptid=211888&pid=2117351