If you are talking about DJI GO 4 (as mentioned above), the Android APP no longer works after the latest Android OS (operating system) update. This happens often. Now, we have to wait for DJI to come up with a new SDK that will work on the new Android OS. This is why I use an iPad to control my drone. Software works better, and never seems to have this problem.
Don't get me wrong, I have an Android phone. The only Apple product I use is the iPad for the drone.
If you want to use an Android product with your DJI drone, you will either have to wait for DJI to update their SDK, or use an older Android device that has not had the OS updated.