Aloha...........Anyone know why when I record from the rc red button on the screen, the recording stops itself after about 20 seconds.  It did not used to do that.  Must be doing something wrong.  Plenty of storage so I don't think that is the issue.  Mahalo for any suggestions........

Hi there, we're sorry for the inconvenience caused. May I know if you are trying to shoot a video? If yes, please make sure that you're on video mode before pressing the record button. If the issue persists, please try to uninstall and reinstall DJI Go 4 App. Should you have further question, please let us know. Thank you.

As Natalia says, make sure you are in movie mode, not still photo mode. If it is still stopping, take the SD card out of the aircraft, copy off any files you want to keep. Then put the SD card back in the aircraft and on the setting part of the RC unit, find the section where you format the card. Perform the format on the SD card and see if that improves the situation.

The reason for doing this is that DJI place a lot of files on the card in hidden folders. These files clog up the card and make it slower to write to. Formatting often removes all thos pesky files.